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On-Line Security

July 31, 2010

About 10 years ago, I had the unenviable task of keeping the virus scanners and Windows installations patched in a university research group. At the time, life was relatively simple: as long as you didn’t open any attachments you were not expecting, or manually download programs you were unlikely to have a virus problem.

Things have changed. Extensive criminal operations prey on software vulnerabilities to try to steal your money and personal information. Just like violent criminals use lapses in your physical security, these on-line criminals use lapses in your software security to try to victimize you. These lapses in your software security allow the criminals to do “drive by” attacks: no user intervention is required. For example, an infected banner ad on your favorite email website could flash a malicious .pdf file to your outdated Adobe Acrobat Reader, and now the criminal can install whatever malicious software he or she desires.

Of particular interest at the moment, is a subsection of malicious software that impersonates anti virus (AV) software. It will pop up messages to the user indicating there are (false) security threats, demanding activation using a credit card before “fixing” these threats. The only real threat, of course, is the program itself and whatever additional malware the criminals controlling it have downloaded to your PC.

See this write-up about one from Norton for more information on one of these programs: There are many more variations on this program.
A friend of mine running Windows 7 and McAfee had this program installed a few weeks ago. I was not fooled by the program’s pop up messages, but found that I could not even open Task Manager to terminate it. The malware was trying to protect itself by stopping task manager and legitimate anti virus programs. Fortunately, I was able to download a file to terminate the malware’s process, and clean it off the PC. Recently, my own PC was attacked. Fortunately, my virus scanner (Norton) stopped the fake AV program from being fully installed.

I thought I would share some useful links with everyone here so you can improve your on-line security.

Removal tools:


Microsoft Security Essentials:

Trendmicro Housecall:

Preventative tools:



Secunia will alert the user to outdated software versions that nowadays are as bad of a security risk as outdated Windows patches. Think Acrobat plugins, Flash plugins and Java.

Sandboxie allows your internet browser to run in a “sandbox”, which means that any malware that does get pushed to your pc is thrashing around inside the sandbox, but can’t get out to your actual PC. An impressive demo video (part 1 of 3) can be found here:

Here are the tecommended best practices from Symantec (

Symantec Security Response encourages all users and administrators to adhere to the following basic security “best practices”:

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device’s visibility is set to “Hidden” so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to “Unauthorized”, requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.
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