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Panda Protection

Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.

Brontok.AN

Threat LevelHigh threatDamageSevereDistributionNot widespread
Common name:Brontok.AN
Technical name:W32/Brontok.AN.worm
Threat level:Medium
Type:Worm
Effects:   It spreads and affects other computers. It displays pop-up messages when it runs, distracting users and affecting productivity. 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 email.
Affected platforms:

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

First detected on:March 17, 2006
Detection updated on:March 17, 2006
StatisticsNo
Proactive protection:
Yes, using TruPrevent Technologies

Brief Description 

    

Brontok.AN is a worm that spreads by copying itself, without infecting other files.

 

It affects productivity, preventing tasks from being carried out:

  • In the affected computer: it displays pop-up windows.

 

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 awaits remote-control orders received through IRC; it changes system permissions, decreasing the security level.

 

Brontok.AN prevents access from programs to websites of several companies related with security tools (antivirus programs, firewalls, etc.).

 

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

  • It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.
  • It terminates its own execution if it detects that a memory dump program is running, such as Procdump.
  • It terminates its own execution if it detects that a debugging program is active.

 

Brontok.AN 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.
  • Email: sending emails that include a copy of itself as an attachment. The computer is infected when the attachment is run.