Threat Description



Aliases: Trojan:​W32/Agent.FVO
Category: Malware
Type: Trojan
Platform: W32


Trojans are malicious programs that pretend be to benign. Trojans do not replicate themselves.


Automatic Disinfection

Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see Removal Instructions.

Technical Details

Trojan:W32/Agent.FVO was sent in several spam runs in the country of Denmark. The e-mail messages are in Danish and were sent to Danish e-mail addresses.The e-mail message claim to be from F-Secure support.The message appears as follows:

 From: Date: 26. August 2008 08:31 Subject: Data er tillagt og sendt med denne meddelelse. Käre kunder! Regning Data er tillagt og sendt med denne meddelelse. Jeg bruger gratis F-secure antispamversion, som allerede har fjernet 338 spambreve. Antispam er helt gratis for private brugere. Attachment: f-secure.rar
The attachment contains a file called update26.08.2008.exe, which, when run, drops a file called dcbcg.exe that attempts to connect to a server located in Ukraine.The IP address to which Agent.FVO attempts to connect hosts a fake version of

File System Changes

Creates these files:

  • %windir%\system32\drivers\dcbcg.exe

Network Connections

Attempts to connect with HTTP to:

  • http://91.203.[REMOVED]/port/c.php?l=US&d=F5CAA48923FD4CCA8D239AE89BEAC0B9&ver=3.6.7&rvz1=2650&rvz2=0000091859

Registry Modifications

Sets these values:

  • HKCU\software\ewrew\dcbcg\main cid = F5CAA48923FD4CCA8D239AE89BEAC0B9
  • HKCU\software\ewrew\sample\maincid = 28280947699F4F27B32917B2C8654CE4
  • HKLM\Software\Microsoft\Windows\CurrentVersion\Run _ = c:\windows\system32\drivers\dcbcg.exe

Creates these keys:

  • HKCU\software\ewrew
  • HKCU\software\ewrew\sample
  • HKCU\software\ewrew\sample\main
  • HKCU\software\ewrew\dcbcg
  • HKCU\software\ewrew\dcbcg\main


F-Secure Anti-Virus detects this malware with the following updates:[FSAV_Database_Version]
Database: 2008-08-26_06


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