Internet Security Tips and Advice

Data backup essentials

January 19th, 2009 by Igor Pankov

Computer security is so multifaceted that it cannot be tailored to fit any one specific definition or approach. Comprehensive computer security comprises numerous subcategories that together add up to form a single, coherent structure. One of these subcategories that we haven’t yet touched on is data backup and the part it plays in keeping valuable data safe. Here, we are making up for this omission by reviewing the different approaches to data backup and how they work.

Backup = Insurance

Data backup enables you to save your information to a safe place and restore it later if something happens to the device on which your data normally resides. It is an indispensable tool if you want to be sure your original work, or files, or whatever data you value stays intact no matter what may threaten that data; it means you can always roll back to a previous state and restore what’s been lost or compromised. When critical information is at risk, data backup is your primary resort to be safe in knowledge that your digital valuables are not jeopardized. Data backup is especially helpful in the following situations:

  • When you’re about to install a new application or a major update and you’re unsure whether it’s going to cause systems disruptions or compatibility or interoperability problems. Ironically, this application could be a security program or Windows Service Pack that introduces significant modifications to your existing OS configuration which may in turn cause other problems. Backing up is also a sensible precaution for users who like to experiment with advanced system settings, like manually tweaking registry entries and testing different system drivers or services.
  • When you experience, foresee, or want to preempt hardware malfunctions. There could be a number of indicators suggesting your hardware may be failing, such as system instability or overheating, or your hard drive is degrading. Hard drive problems really need a whole article to themselves, but for the purposes of this article, there are a few warning signs you should be aware of. When a hard drive is nearing the end of its life, Windows starts to report disk readability or writeabilty issues, or the SMART hard disk diagnostics system warns of an impending crash and recommends you promptly save and transfer your data to a safe place. Backing up is also advisable if you don’t use a UPS (uninterruptible power supply), as an electric surge can make your hard disk or motherboard unusable beyond repair. It’s hard to predict a future malfunction, but not impossible. Experienced users know of potential problem indicators, but for everyone else, here’s some advice: the older your system is, the more chance there is of it failing because of lack of proper servicing or care. If it’s kept in a dusty, humid or hot environment, the likelihood of failure is higher. It’s a good idea to run a free-to-try diagnostics utility such Sisoftware’s Sandra or Everest from time to time, as these tools can be helpful in predicting hardware crashes.
  • Backing up also makes sense if you want to mitigate the impact of viruses and other malware programs that may get past your defenses. Beyond their primary mission of stealing information, malware can be more directly destructive by damaging system configuration settings, corrupting files, and blocking or diverting network connections. As we’ve repeated many times in Security Insight, the use of security software is only one layer in the quest to safeguard your data, and no security solution can keep you safe from every threat. Backups can often be a more effective way to restore your system after a malware infection than antivirus.
  • You intend to use your computer on-the-go and are concerned about data integrity or safety. If you lose your laptop or if it ends up in the water, a backup of your important data will save the day.
  • You may be the unofficial tech support person for your friends and relatives. If anything goes wrong with one of their machines, you can simply roll it back to the last backup data.
  • A backup is handy if you plan to change to a new PC. Just save all your files and restore them on the new PC. It’s important to remember, however, that if the configuration of a new PC significantly differs from your old one, restoring the operating system and all installed programs won’t be possible, because the different hardware will likely require different settings.

What can be backed up

When you select items to back up, consider what is important to you. Essentially, the following can be backed up:

  • Individual files and folders (documents, photos, music, etc). With your backup software, simply designate those items that you want to be backed up and it will save them automatically. Don’t forget to update your backups regularly to take care of new files and updated originals.
  • Local and remote storage, including logical disks (partitions) and physical disks. In addition to files, your backup system can save the entire contents of selected hard drives and later restore their contents to a new or old destination.
  • Removable storage, such as USB flash drives, DVDs and other external devices.
  • Your operating system and its settings, including all installed software. You can save the state of your operating system and then revert back to the last image point when needed.

How it works

Modern backup software is relatively easy and straightforward to use. Generally, after you’ve installed it, you select the locations that you intend to backup, specify the location where these objects will be stored and press ok. Once the backups are created, you can restore them when needed. Your first backup should always be a full copy of the original location, whereas subsequent backups are incremental, backing up only content that is new or changed since the last backup. This saves time and disk space needed for backup.

Later backups can be either on-demand (you ask the program to perform backup at a desired time) or on schedule. On-schedule backups can be set to occur at regular intervals specified in the backup program itself. You might also want to consider on-event backups offered with select programs, which can be set to occur when a certain event, such as prolonged idle time or a power problem, are indicated.

Backup storage

When you back up your data, you save it to a specific destination. Usually, this destination is a large compressed file on a local device – either a removable hard drive or a high-capacity memory card. The backup location can be customized and it’s very important to keep in mind that the place where you store your backup copy should be secure – if your primary data source fails, you need to be sure you can access and use your backup. Keeping your backed-up data in a safe, dry place disconnected from the power circuit will ensure your backup will stay in good shape and enable you to get your data back in case of emergency. It’s not a good idea to keep your backup copy on your primary hard drive or an old ROM disk, because these can be exposed to disaster as much as your main storage.
You can back up your data to remote storage or use one of the free or commercial online backup services available. Bear in mind that storing your data at somebody else’s facilities has advantages and drawbacks. The advantages are:

  • Your backup is not affected by local events, such as power surges, lightning, fire, flooding, earthquakes and other natural disasters.
  • Storing your data with a credible organization that has expertise in data storage and continuity operations is generally reliable. Such organizations generally run fault-tolerant systems with multiple backups that should ensure your data will be safe.

Disadvantages are:

  • You have to trust the organization where you store your data, to be sure its confidentiality is maintained.
  • Uploading your saved data and later downloading it to restore from will require a lot of bandwidth and data support, so your ISP account should allow for unlimited data and high throughput.
  • There’s some concern over the security of your data when it is in transit. The risk is small, but it could be accessed by third parties. In that regard, check with your backup provider concerning the precautions they take to make sure this process is safe.
  • Managing your remote backups may not be as simple as local backups, and remote backups don’t always give you the full benefits of local backups. As an extreme case, you would not be able to restore a backup if your computer is so damaged that it cannot boot the OS. You’d have to use another computer to connect to the internet, download the required remote image and initiate the restoration process. In contrast, local backup software usually offers the option to create a CD-ROM boot disk that will initiate restoration to the desired point if your computer cannot be started in the usual way. You simply insert the CD, connect to the device on which you keep your backup, and your hard disk is restored in an hour or so.

Forms of backups:

The following forms of backup exist:

  • Disk cloning, where your entire physical drive is copied onto another hard drive. In case anything happens to your original drive, you can simply connect a new drive to your PC and it will boot from it. The new drive will be an exact copy of your original drive, and will have all the files and documents as existed on the old one at the moment of cloning operations. If the size of the disks differs, your partitions (logical disks such as C, D, etc) will be shrunk or expanded proportionally. If you make a clone of the disk, remember that the computer configuration should stay the same.
  • File storage, where all backup data is compressed and stored in one single file. This file is compressed to save space and can be password-protected to ensure other people can’t view its contents.
  • Restore points selectable within your backup software. Restore points are assigned according to the date a backup was made, and if anything happens to your PC, you can always revert to the last restore point from within the program interface.

Different flavors of backup solutions

Computer backup solutions exist in both software and hardware forms. Hardware systems are usually automated, always-connected devices that copy the contents of the primary hard drive to an embedded magnetic tape or hard drive. Mirrored Raid Arrays (RAID-1) are two internal hard drives running in parallel mode, where the second drives automatically backs up the contents of the first drive on the fly. If the primary drive becomes corrupted, the contents can be recovered from the second drive. Effective against hardware HDD failure, RAID arrays are of no use in case a virus harms your main system, because the same infection will be instantly duplicated to the second drive as well, negating all efforts. RAID systems are relatively easy and inexpensive to deploy, but require a degree of expertise to manage in the first configuration stages.

Back-up functionality is present in many of today’s software applications, from Security Suites such as Norton360 to OS-bundled software such as Apple’s Time Machine and Windows’ Backup or Restore Wizard. These programs usually offer less functionality than dedicated, specialized backup tools such as Acronis True Image, but still perform basic backup tasks and are quite sufficient for many people.


Backing up your system is a very good habit to develop. It will save you a lot of hassle and stress in case a system malfunction or virus infection occurs. There you have it, folks – I hope you found this article informative and useful.

Posted in Security Insight | 6 Comments »

All you need to know about security leak tests

October 29th, 2008 by Igor Pankov


The term leak test, or leaktest, has become a popular buzzword among the security cognoscenti in the last couple of years. It’s in the news, it’s in the comparison charts, but what does it really mean? Why should regular PC users be concerned with leaktests and their implications in their day-to-day computer activity? How do leaktest results help you when it comes to choosing a robust security product?

These are just a few of the questions this article aims to answer. After reading this material, you’ll have all the information you need to understand leak tests and interpret their results.

What is a leaktest?

A leaktest is a tool or a set of procedures that attempts to determine a security product’s ability to prevent outbound data breaches that are designed to steal or compromise your personal information. As the name implies, leaktests are used to find out if a security product reliably protects your data against accidental or deliberate transmission through security barriers, often called data leak prevention.

Leaktests have been in existence since the appearance of the first personal firewall products more than five years ago, and their main objective has been to test the firewall’s ability to prevent unwanted applications from “phoning home” or otherwise communicating data across the Internet without the user’s consent. Leaktests have recently evolved into a broader category that includes tests using the simulated termination of a security product’s operation, controlling advanced program interactions, and other complex technologies that hackers might use to target personal information stored on users’ PCs.

If a product passes a certain leaktest, it means that the product has successfully blocked a would-be attack that’s based on a specific intrusion technique. There are many techniques known to be in use by hackers, and a robust security program should be ready to detect and rebuff all of them. New techniques are constantly being created by miscreants to get hold of personal data, so vendors of security products are constantly developing countermeasures to ensure their customers are properly protected.

When Windows XP came out in 2001, a number of malicious programs, like Trojans and spyware, already existed that could easily steal valuable user data such as login credentials or credit card information and transfer them to unauthorized third parties. In an effort to stop these breaches, security firms came up with firewall solutions that would block network activity initiated by malevolent applications by denying them outbound network access. To test firewalls’ performance, security professionals developed special tools that emulated attacks; these tools checked if the firewall was able to block such attacks from connecting by asking users to decide whether the activity should be permitted. These first leaktests were quite primitive, but they managed to expose significant deficiencies in certain firewall products.

The first leaktests used simple methods such as file name spoofing or running a trusted application with additional parameters that instructed it to send a certain text string to a target location with the goal of fooling the firewall into seeing the application as a trusted activity acting on its own behalf and consequently allowing this transfer. The earliest well-known leaktest was GRC’s Steve Gibson’s “Leak Test”, which simulated an attack in which a malicious application would rename itself to Internet Explorer (a legitimate Internet-enabled application) and determine whether the firewall was able to detect this change.

Much has changed since those days, and today’s leaktests are way more sophisticated, using advanced interaction mechanisms and network properties to simulate the data mining capabilities typical of today’s malware.

Leaktests examine the proactive protection capabilities of security solutions, checking how they respond to a particular intrusion technique, or attack vector. This is very different from the process used to examine antivirus solutions, where tests are used to determine whether a solution is resistant to a specific malware sample.

Techniques employed by leaktests

Leaktests are too varied to fall into convenient classifications for their operations, and most are based on different techniques for testing security products. These techniques are constantly evolving and improving, and the more leaketsts exist, the more rigorously security solutions are tested.

To generalize, leaktests will try to emulate one of the following techniques:

  • Impersonating a legitimate application installed on a computer or leveraging its access credentials to send information to the Internet (i.e., spoofing, trusted application launch with special parameters)
  • Interacting with a legitimate application using embedded Windows controls such as OLE Automation or DDE requests
  • Modifying active applications in memory, attaching malicious components to benign applications – for example, component injection, direct memory patching, creation of malicious threads
  • Using trusted network services and protocols to send unauthorized data in the hope that the firewall will miss the unconventional activity; such activities might include false DNS requests, BITS service exploitation, or lax ICMP filtering
  • Installing a new network adapter driver through which to route data
  • Disrupting or disabling the protective functions of an installed security application
  • Initiating system shutdown to check if the firewall monitors the activity of untrusted processes through to its completion
  • Intercepting keystrokes

Synopsys: program interactivity

The majority of leaktests were designed for Windows XP which, unlike Vista, does not verify a program’s permissions to interact with other installed programs or perform any other activity from the list above if the user has Administrator privileges. This situation creates the potential for exploitation, as any malicious program can piggy-back on a trusted, legitimate program as a means of carrying out targeted attacks. Gone are the days when malware would attempt to steal user data itself; now, it would use a legitimate application’s network access credentials with the firewall to transmit data. Security solutions need to be able to not only detect malicious programs, but be prepared to monitor the integrity of legitimate applications and the use of network resources for the advanced leak techniques used by malware.

Tradeoff: wordy alerts versus looser control

Thousands of internal interactions occur on a PC every hour. Of course, only a fraction of these are malicious. So if the firewall monitors and prompts the user regarding each operation, the user will be bombarded with alerts, making it impossible to do anything productive on the computer. As a solution to this limitation, security vendors have implemented a mechanism that “memorizes” a user’s response to a particular event so that, next time this event occurs, the previous input will be used to handle the event, and no alert is displayed. Additionally, vendors of leading security solutions such as Outpost Security Suite Pro, Kaspersky Internet Security and Comodo Firewall use online databases to automatically designate permissions for the majority of Windows applications, so the decisions are made in the background, without interrupting the user’s normal PC use. Windows Vista, with its new User Account Control (UAC) functionality, has made significant progress in stemming illegal or unauthorized activity. It does this by lowering the privileges until the user has allowed a particular operation by okaying the UAC’s foreground prompt. Unfortunately the responses given cannot be memorized, so the alert window displays start up again, frustrating the user once more.

Other vendors, such as Symantec and ESET, have chosen to control fewer events on the user’s computer, reducing the number of prompts displayed to the user. The downside of this approach is that the level of monitoring is reduced, resulting in less control over activities and the potential for some techniques actively being used in malware could bypass the protection. It’s no wonder, then, that these solutions fare quite poorly in group tests. Time will show who has the better approach, but considering that malware is becoming more sophisticated, an effective security solution really needs to control the maximum number of events on a computer, and require less user interaction.

Leaktest usage

Leaktests are safe applications designed to verify if a firewall is able to prevent an attack that uses different techniques to steal data. Leaktests can be downloaded from the Internet and executed on a user’s machine. If the security solution displays an alert when the test is run, it means that the solution successfully detected the leaktest activity and would most likely be able to deter real-world attacks based on the technique used in the leaktest.

Although successfully passing a leaktest doesn’t always mean the security solution is bullet-proof, it essentially means that it will do its best to protect a user in case a real attack strikes.

Interpretation of results

There are specialist organizations that carry out leak testing, the most active of which are Matousec Transparent Security and Firewall Leak Tester. They have vast information resources and update their leaktesting results whenever new security products come out or when updated leaktests are released. As a rule of thumb, the closer a security program to an absolute pass score of 100 percent, the more resistant to malware attack it is.

Leaktests versus other testing mechanisms

As noted earlier, leaktests test how well a security solution is equipped to combat malware that uses different intrusion techniques to bypass outbound protection. Leaktests are technique-centric, as opposed to virus testing, which is largely signature-oriented. Leaktests verify the potential of a solution to deter unknown attacks without the use of a particular threat signature.

The benefits of leaktests

It is hard to overestimate the contribution leaktests make to the security community. Leaktests are the primary techniques used to test whether a security product is capable of keeping unknown malware at bay by restricting its activity within the software environment of a PC. Leaktests have a practical value to the end user; many product reviews are complemented by leaktest results, which should give you a good indication of how well a security product is able to keep you safe from today’s widespread anonymous threats.


We hope this article has shed some light on the concept of leaktests and their relevance in testing the ability of a security product to prevent unauthorized outbound data leakage. Leaktests serve as a practical and effective tool in measuring the quality and scope of protection against the kinds of advanced breaches that are used to carry out actual attacks.

Posted in Security Insight | 3 Comments »

Debunking common security myths

September 15th, 2008 by Igor Pankov


Over the summer, I started thinking about why people think about security the way they do, and what might be causing people to make elementary mistakes when securing their computers. I’m not talking about the choice of products or the measures they take to keep their computers secure, but rather what is fundamentally flawed in the way they think about security. As I found out during conversations with people as I travelled around Europe, most users’ security knowledge is far from what I, as a so-called ‘security expert’, might consider adequate. As I delved deeper into the subject, I discovered that quite a large number of users have completely wrong ideas and misconceptions about how to tackle security issues. These conversations prompted me to write this article in an attempt to correct the most common myths and misconceptions.

Myth #1:
I will be perfectly safe if I get the best security software and keep it up-to-date, – that’s all I need to do

It’s true that use of reliable software to shore up your computer’s defenses is vital, but before that comes careful and intelligent use of your computer to prevent security incidents in the first place. It is a truism that the weakest element in the security chain is the computer user himself. In my view, relying on security software alone is like relying on car’s crash test results to ensure that you’ll be unscathed after a major wreck. But I think we would all agree that it’s better to drive safely, wear a seatbelt, and obey the speed limit. The same applies to security: you need all the safety systems, but if you don’t adhere to basic standards of safe conduct, you put your computer at unnecessary risk. So think before you open unknown files or email attachments, or react to spam and phishing attempts – these are most likely designed to undermine your security. Also, don’t forget to install latest Windows and programs updates to keep you safe from known vulnerabilities found in vendors’ products. Remember, no matter how strong your preferred security program is, it will have one of the following weaknesses:

  1. Your anti-virus can’t recognize every virus in existence and is consequently not equipped to provide complete protection. A variety of factors contribute to this, including reliance on virus signatures and heuristics — based instruments — that struggle with the detection of different and ever-changing virus behaviors.
  2. Your firewall or HIPS may have one or more of the following weaknesses. Both MAY exhibit delayed reactions to a security incident. Both can sometimes miss an unwanted/illegitimate operation simply because these solutions cannot detect every possible type of system/network operation. Leak tests, no matter how theoretical their scenarios might be, serve as a good (but not perfect) indicator of a solution’s protective thoroughness. These systems may also fail to activate when it’s most needed – when a new attack strikes.
    Rootkits and system interceptors that remain invisible to the operating system and the majority of security programs can be used to hide the presence of a malware payload. Rootkits are being increasingly adopted by hackers to mask malware operations such as spam, botnets and Denial of Service (DoS) attacks.
  3. Security software sometimes interferes with normal operation of a PC, impacts its performance or displays alerts and action prompts that might be confusing for a normal person to respond to. It can also block WiFi connectivity or report false positives that may accidentally delete a legitimate file.
  4. Some security programs require that, once infected, manual remediation be used to undo the changes brought by malware – a task beyond the ability of most normal computer users.
  5. Your security program turns out to not be the trusted software you thought it was but instead is a rogue program that only advertises a promise to protect.
  6. Antispam and antiphishing solutions produce a high number of false positives, and phishing sites are so short-lived that, by the time a security company issues a security update to block the domain, the location has already harvested its share of stolen IDs and financial data and moved on.

Myth #2:
Why would I be hacked? I’m small fry, I’m not interesting to hackers

People do a lot of different things on the Internet, and sometimes they expose personal data. An average internet user is vulnerable to these kinds of threats:

  • Theft of personal or financial data. We shop, we enter our credit card numbers and other personal details. This creates risk and the data could be abused if you’re using an unprotected PC. A keylogger could be silently monitoring your keystrokes and capturing everything that you type on your PC; later, it will communicate this information to the hacker who sent it out hunting. If you shop and the channel of communication (i.e. the web browser traffic) is not encrypted, everything that you send over the Internet is vulnerable to being copied and used without your knowledge. Your log-in passwords, email and social network accounts can also be hijacked in a similar way. Using both known and new techniques, a sophisticated hacker can eavesdrop on your Internet sessions using what’s called "man-in-the-middle" techniques to intercept and later exploit seized data. To protect yourself from such threats, it’s vital that you use a robust firewall and ensure traffic is transmitted over an encrypted route.

And that’s not all.

  • Botnet infections, where the victim’s computer and Internet bandwidth are hijacked and used to harm other Internet users. Botnets are responsible for spewing out spam or phishing attacks that look like they come from the victim’s computer, and may also be used to conduct distributed Denial of Service attacks on legitimate organizations and take control of the organization’s website.
  • Hackers are always on the lookout for a vulnerable PC on the network. Once found, these PCs are earmarked for later use for nefarious purposes. By using special tools to probe for exploitable machines, a hacker doesn’t target a specific host, but rather, thousands of poorly protected computers that can be amassed in a matter of minutes.

Myth #3:
My company uses a gateway firewall, so I have nothing to worry about

Gateway firewalls, if properly configured, provide solid perimeter protection for your company. Malicious inbound data will be blocked and hackers probably will not be able to break into your PC. But outbound data can still leave your computer, meaning passwords, financial data stored on hard drives, and other critical resources will still be accessible to attackers. Plus, being protected from outside doesn’t necessarily mean you’re safe from hackers inside your company’s borders. You could be inadvertently attacked by a colleague who’s become a victim of, say, an Internet worm that spreads by sending itself to all contacts listed in someone’s address book.

Myth #4:
I only visit "good" places on the web, I never visit objectionable or adult sites. So I am safe from threats that spread over the Internet

If you’re being truthful, I’d say you’re in a low-risk group. However, there are some things to keep in mind as you surf around legitimate websites:

  • Sections of legitimate sites can be hijacked as easily as adult sites, and bad content placed on them temporarily until the problem is detected by the site’s operators. This happened to the Bank of India’s website not too long ago. Additionally, legitimate sites often incorporate Flash animations and JavaScript code that may be vulnerable and open up a backdoor to your computer. And last but not least, cross-site scripting (XSS) vulnerabilities may be employed by attackers to capture your logon session. You can read about XSS in greater detail here.

Myth #5:
If I connect to a credible WiFi provider like British Telecom at the airport, my Internet connection is protected

We’ve covered the secure use of WiFi extensively in other articles, but it seems the message still has not fully got through to people. If you use an unencrypted wireless signal, regardless of the network provider, even a novice intruder can easily read what you send or receive over the network, so don’t ever take the risk and post anything confidential over a public WiFi connection.


Well, I hope this "back to school" article has served to remind you that, whatever protection you have on your machine, security still begins and ends with not taking unnecessary risks while you’re online. It’s a lesson every Internet user needs to learn.

Posted in Security Insight | 6 Comments »

Cross Site Scripting – the Web’s lurking danger

July 23rd, 2008 by Igor Pankov


There are some areas of computer security over which a user has almost no control; from involuntary exposure to software vulnerability exploits to hijacked DNS servers that divert visitors to infective locations, there is little that a user alone can do to avoid becoming a victim.

These challenges – as well as a multitude of others – require action by software vendors to design less vulnerable products and by responsible authorities to deploy an Internet infrastructure that’s less vulnerable to abuse – or at least enable fast mitigation when flaws are found.

The same principle can be applied to cross site scripting attacks. This type of web compromise cannot be solved by individual Web users alone but should be the responsibility of web application and browser developers. However, it appears this level of prevention won’t be available for some time, so it’s important to recognize the impact of cross site scripting vulnerabilities and minimize inadvertent exposure wherever possible. That’s the topic of this article.

What is cross-site scripting?

A script is a set of machine language commands processed on a user’s computer or by a web server. Cross-site scripting (XSS) vulnerabilities occur when scripts originating on one website (usually a malicious site) are permitted to interact with the content of another website, or an HTML page stored locally – hence the term “cross-site”. Unlike other types of attack, the perpetrators of cross-site scripting attacks use vulnerable servers as an intermediary to stage attacks on visitors to compromised websites; they do this by forcing the user’s browser to run the scripts placed on those vulnerable web servers.

XSS vulnerabilities first appeared at the turn of the century, when a number of security experts reported concerns over the potential use of JavaScript code with malicious intent in a cross-boundary attack.

In an XSS attack, after the script has been executed on the user’s PC, it starts issuing commands and remotely controlling the behavior of the target browser window in such a way that it appears the user is performing these actions himself. The script may execute locally on the user’s computer or lie dormant on the web server, attacking other users as they access this page.

The problem with XSS is so significant because, as a result of an XSS exploit, the script takes control of the victim’s web session while the attack is carried out in the background, leaving no footprint behind and thus making it extremely hard to detect.

In order for XSS attacks to succeed, certain criteria must be met: the use of flawed browser software that does not validate the script’s origins and permissions, or poorly-written Web server code that does not exercise proper validation routines. Social engineering is also widely used to lure victims into clicking the link containing the malicious script.

To give an idea of the scale of the problem, it is estimated that more than half of all websites today have XSS holes, and XSS flaws account for more than 80 percent of all documented web vulnerabilities. Almost every well-known web portal has been compromised by XSS attacks at some time – the likes of Google, MSN, Facebook and other prominent sites have experienced XSS exploits first-hand.

Different types of XSS

There are currently three types of cross-site scripting vulnerabilities:

  • Local, or Type 0, XSS, where the problem exists in the client-side script of a web page. To exploit the vulnerability, an attacker constructs a web page with malicious JavaScript code in it and sends potential victims a link to it (via email, IM, etc.). Once the link has been clicked, the script executes and serves up a locally-created vulnerable HTML page which contains JavaScript code that can be run with the the current user’s privileges (most users log on as Administrators). After that, an attacker can gain access to the victim’s local computer, including viewing files and other sensitive data.
  • Non-persistent, or Type1, XSS is one of the most common, and involves vulnerabilities of server-side scripts that do not sufficiently validate user input. Non-persistent XSS occurs when a user receives a link with malicious script while logged on to a web site. After the link is clicked and the malicious script executed, it hijacks the user’s session and controls the activity of the page the user is currently on. This type of compromise can be executed in the current browser session only.
  • Persistent, or Type2, XSS is the most blatant and dangerous vulnerability because it can affect many users without the use of much social engineering. The vulnerability is in the server-side scripts but can exist for a long time, so it can affect a much greater number of users. It arises when a legitimate server persistently stores portions of malicious scripts placed on it by the hacker and later feeds that code to the visitors’ browsers for the latter to execute.

What the perpetrators are after

Most attacks target session cookies – files loaded onto users’ machines by the web sites they connect to. Cookies are easy mechanisms for identification on the site, so once the perpetrators get hold of your cookie files, they can impersonate you and act on your behalf. Cookies are transferred to attackers by the commands in the script.

What victims can lose

As a result of successful exploitation of an XSS hole, victims may lose important data and be exposed to ID theft. Once your session has been hijacked, the “script masters” can perform any activity that a legitimate owner of the compromised account can do – read and delete emails, perform financial transactions and credit payments, create postings on social networking sites – just about anything the legitimate user is authorized to do.

What makes XSS attacks possible?

XSS attacks happen for two reasons: sloppy programming and haphazardly-created website engines that do not filter user input. Either of these situations can enable a malicious user to insert a piece of a JavaScript code in, for instance, a search field; the server would return a results page along with the original search query, which could be interpreted by the client software as executable code. So it’s important that web developers create code that filters user input and translates certain characters used in JavaScript into plain text, not executable commands.

Another contributing factor to XSS vulnerability is the use of outdated web browsers that don’t apply the necessary security policies when processing (parsing) code coming from different sources.

How can users protect themselves?

While developers carry much of the blame for the majority of XSS attacks, there is still something a web user can do to minimize vulnerability. The key element is preventing client-side code from being sent to the browser by untrusted websites. Internet Explorer users can do this by raising their security slider to “High” in the Security tab, restricting the ability of any potentially malicious code on any website to run, and specifying a list of sites that are still allowed to run code. Firefox users can use the NoScript addon to block JavaScript and only allow it on sites specified in the exclusion list, as it is the case for IE. Another option would be to increase the Privacy setting in IE so that no permanent cookies are stored by the browser, and to specify a set of exclusions.

Another useful habit to get into is to always log off from a web session when it’s completed, and to open unknown links only after the user has left the site (the cookie file is removed from local storage and no attack is possible).

It’s also important to keep your browser and Windows up to-date so that any past vulnerabilities won’t apply to leave you vulnerable.


XSS attacks arise because of errors in web code that does not sufficiently check user input for malicious executable code. Vulnerability is avoided if potentially-malicious data that a user submits to a server is extracted and returned as plain text (non-executable) data. While we wait for a solution from web application developers, there are actions users can take to minimize their exposure to XSS: logging off from a session before clicking and following any links, disabling JavaScript code for unknown sites, using the latest versions of web browsers. And lastly, continue to follow the ‘rules of the web’ – don’t open links from strangers and don’t trust contacts you don’t know.

Posted in Security Insight | 2 Comments »

Welcome to the research section

July 3rd, 2008 by Igor Pankov

In the first of our series of research, we decided to pit against each other three popular security products – Kaspersky Internet Security, Agnitum Outpost Security Suite Pro and Eset Smart Security to find out which demonstrated the best aptitude to counter threats with the help of onboard proactive protection instruments – those that monitor system activity and alert to new or unknown program operations.

The testing methodology was quite straightforward: disabling all signature-related scanners, running the test malware sample and tracking how each product managed to prevent activation of malware after system restarted. All prompts were given the “block action” response, and the tools used for testing were Sysinternals Autoruns and Process Explorer.

Click the corresponding video file to see the products in action.


Video 1 – Product in action:
Outpost Security Suite Pro

View Video


Video 2 – Product in action:
ESET Smart Security

View Video


Video 3 – Product in action:
Kaspersky Internet Security 7.0

View Video


Posted in Research | 11 Comments »

Useful Security Links (June 2008), Part 3

June 26th, 2008 by Igor Pankov
  1. Malicious Trojan Horse Plagues Apple Mac OS Users
  2. 20 million Firefox 3 downloads in a week, ~4% market share
  3. Trend Micro’s CEO says ‘AV industry sucks’
  4. Software update snafus block Microsoft patches
  5. Cisco IOS Rootkit Demonstrated

Posted in Useful Security Links | No Comments »


June 20th, 2008 by Igor Pankov

Encryption is a way of securely storing or transferring data by using special encryption key or algorithm to cipher its contents. For anyone else except the target recipient, the encrypted source will appear as a piece of unreadable, garbled data, making encryption a valuable instrument to hide private or secret information from strangers.

The target recipient possesses the unique decryption key which enables to decipher encrypted data and thus arrive at the original content. If someone manages to get hold of the unique decryption key, he/she can read that data as well. That’s why it’s important to keep the key in secure, tightly guarded location.

Posted in Security Glossary | No Comments »

Useful Security Links (June 2008), Part 2

June 16th, 2008 by Igor Pankov
  1. How to Remove Your Browser Hijacker
  2. Trojan Makers Block PC Functions To Promote Rogue Anti-Spyware Programs
  3. McAfee CEO: Adware is killing AV blacklisting
  4. Keeping our Technology-Savvy Kids Safe Online
  5. Obama Campaign Hopes for Better Web Security

Posted in Useful Security Links | No Comments »

The Perils of Social Networking

June 16th, 2008 by Igor Pankov


According to some estimates, more than thirty percent of US web traffic is taken up by users interacting on social networks like Facebook, Myspace and LinkedIn. Social networks (SN) can be fun and useful places to be when you want to hang out with your friends online, meet new colleagues, discuss a news event or engage in hot-button debate. The primary benefit of social networking is that it connects people with common interests or occupations and provides an easy way to share information, opinions, photos, videos, and just about everything else.

But there are also drawbacks to the open environments that constitute social networking. As you may have guessed from the title, the dark side of social networking is the focus of today’s article.

Basic guidelines

Registering with a social network

When you first sign up, you’re required to provide your real name and a valid email address that your future account will be associated with (your email address is usually used as your username for the SN). Make it a rule to choose at least a six-character strong password for your account. Also remember that passwords for your registration email address and SN login should be different, so that in the unfortunate event your account is compromised, you can always reset the password by using your email to restore your SN credentials; this presumes that the perpetrator cannot access your email inbox and read incoming messages.

Minimizing vulnerability exposure

Whereas Windows is your offline desktop platform that you can manage and secure to the best of your knowledge or expertise, your online social networking platform resides on remote servers over which you have no control; your SN identity and activities are only as well-protected as the underlying SN engine.

So, it is up to you to protect yourself – we suggest following these ‘safe practices’:

  • Use the latest browser software and install Windows Updates as soon as they become available.
  • Use a firewall to protect your system against unknown threats; use up-to-date antivirus to block known threats and intrusion prevention software to alert you to potentially dangerous activities on your computer.
  • Do not download, open or respond to content published or sent by unknown people. There has recently been a virus outbreak in the Russian portion of an SN that resulted from unwary users clicking on a reference to a fake image file that led to the activation of a virus that then wiped user data from the affected computers.
  • Remember that SN is still in its infancy: the engines are still immature and the platforms are vulnerable to determined attackers. Reports of faulty SN code appear regularly in the media, and you cannot rely on the integrity and non-disclosure of your personal details due to multiple weaknesses in SN systems. Cross-scripting errors (XSS) enabling attackers to view restricted sections of user data have affected almost every SN site, much like the way spyware targeted Windows systems that had not been patched with SP2 back in 2003.
  • The 3rd party applications (widgets) that Facebook and Myspace offer as additional downloads are even more problematic. These programs are not tested for compatibility or security defects, so be sure you understand exactly what you are installing when you choose to use one of these applications.
  • Don’t access your online profile from public computers – such actions are fraught with additional risk because of the potential for theft or malware compromise. Your log-in details might be stored in a local cache and later extracted and used to illegally access your profile, or the computer may be infected with keylogger that will silently capture any piece of information, including log-ins and dialog sessions, and relay this data to unauthorized third parties.

Privacy precautions

Do not disclose sensitive information – ever!

A recent British survey revealed that more than half the SN users interviewed publish contact details and private details in their online profiles, making them the easy targets to ID thieves and other miscreants.

Due to the open nature of the Internet and the fact that your account can be hijacked, coupled with the vulnerabilities of SN platforms, you should NEVER publish any sensitive information about yourself, like your home address, Social Security or cell phone numbers. And don’t post anything that could backfire against you, like videos of your student parties, or anything else that you wouldn’t want a prospective employer to see.

Prevent anonymous users from viewing your profile

By making your profile private, you limit access to your online profile only to friends and people you know.

Authorize and add as friends only people you know

The smaller your inner circle of friends, the more private your online profile is.

Never trust online-only acquaintances

It’s important to keep in mind that people and their identities are not always what they claim to be, and you should not blindly trust people that you meet online. Don’t meet these people in real life except in very public, safe places, and you must strive to avoid any other physical contact with them.

You may have heard the dramatic story of a girl committing suicide after her online date supposedly let her down, whereas in fact the cheating partner was the mother of a teenager who didn’t want her son to date the girl. If she had been a little less trusting of what she read online, she would probably be alive today.

Favor sites that use encryption

Facebook, for example, encrypts your interactive sessions, whereas Myspace hasn’t yet followed suit. Encryption garbles data in transit so that no-one can read intercepted information, protecting your passwords and other information from outsiders.

Report abuse

Should you encounter cases of spam, harassment, stalking or other intrusions into your private life, you should report such incidents to the people responsible for proper conduct on the social networking site. Consult the FAQ or Contact Us section to find specific contact information.

Don’t access SNs from your workplace

Research indicates that half of the workforce access SNs during the workday, reducing productivity and distracting from work-related issues. Such activities may also be in violation of your employer’s “appropriate Internet use” policies.


Social networks are growing in scope and number of subscribers. People use it for business, personal and leisure contacts. It’s important to remember that the information you provide about yourself is easily available even if you designate your online profile as “private”, so never publish any information about yourself that can be used to hurt you. Remember, employing safe internet usage practices, common sense and knowledge is the best protection online.

Posted in Security Insight | 5 Comments »

Lower user privileges

June 13th, 2008 by Igor Pankov

Working with the rights of an Administrator is not advisable because admins are highest in a user hierarchy and therefore are allowed to exercise full control of a system. If the user is logged on with admin’s privileges, he/she can start any program, install any driver, register arbitrary service and do just about every other type of activity that could be dangerous to a PC. If malware is unknowingly started with the admin rights, it can do whatever it wants.

On the other hand, if a user is logged on as Restricted User, for instance, he is not allowed to make critical modifications to the system and run vulnerable services. This limits the impact of possible malware if it’s started from the limited account.

Users can designate/change account properties from the Control Panel’s User Accounts menu by clicking “Change my account type”.

Posted in Security Tip of the Week | 5 Comments »

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