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Panda Protection

Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.

Kolabc.BS

Threat LevelLow threatDamageHighDistributionNot widespread
Common name:Kolabc.BS
Technical name:W32/Kolabc.BS
Threat level:Medium
Type:Virus
Effects:   It carries out damaging actions on the affected computer. It uses the infected computer to take malicious actions on other users. It carries out actions that decrease the security level of the computer. It uses stealth techniques to avoid being detected by the user. It uses anti-monitoring techniques in order to prevent it being detected by antivirus companies. It spreads , via IRC, via mapped drives, through shared network resources, through instant messaging, by infecting files that are then distributed.
Affected platforms:

Windows 2003/XP/2000/NT/ME/98/95

First detected on:April 22, 2010
Detection updated on:April 22, 2010
StatisticsNo

Brief Description 

    

Kolabc.BS is a virus that spreads to other computers by copying its code to other files or programs.

 

It affects productivity, preventing tasks from being carried out:

  • In the affected computer: it converts the computer into a platform for taking malicious action surreptitiously: spam sending, launch of Denial of Service attacks, malware distribution, etc.

 

It reduces the security level of the computer: it terminates processes belonging to security tools, such as antivirus programs and firewalls, leaving the computer defenseless against attacks from other malware; it listens on open ports in order to control the computer remotely; it awaits remote-control orders received through IRC or FTP; it changes system permissions, decreasing the security level.

 

It uses stealth techniques to avoid being detected by the user:

  • It uses techniques included in its code to hide itself while it is active.
  • It terminates processes corresponding to several security tools, such as antivirus programs and firewalls, to prevent detection.
  • It deletes the original file from which it was run once it is installed on the computer.

 

It uses several methods in order to avoid detection by antivirus companies:

  • It terminates its own execution if it detects that it is being executed in a virtual machine environment, such as VMWare or VirtualPC.
  • It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.
  • It terminates its own execution if it detects that a debugging program is active.

 

Kolabc.BS uses the following propagation or distribution methods:

  • Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
  • IRC: It sends a copy of itself to all users connected to the channel to which the infected user is connected.
  • Instant messaging: it sends links pointing to a copy of itself to all users included in the infected user's contacts list.
  • Computer networks (mapped drives): it creates copies of itself in mapped drives.
  • Computer networks (shared resources): it creates copies of itself in shared network resources to which it has access.
  • File infection: it infects different types of files, which are then distributed through any of the usual means: floppy disks, email messages with attachments, Internet download, files transferred via FTP, IRC channels, P2P file sharing networks, etc.

 

Kolabc.BS uses the following infection strategies:

  • Resident: once it has been run, the virus goes memory resident and stops functions belonging to the operating system. Therefore, every time the operating system or an application tries to access any of these functions, the virus will activate and infect new files.