Virus:Win32/Gael.D is a file-infecting virus that targets .EXE files.

What to do now

Manual removal is not recommended for this threat. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as Microsoft Security Essentials, or the Microsoft Safety Scanner. For more information about using antivirus software, see

Threat behavior

Virus:Win32/Gael.D is a file-infecting virus that targets .EXE files.
When a file infected with Virus:Win32/Gael.D is executed, the virus initially checks if the mutex "gaelicum" exists. If it does, this virus transfers control to the infected host file; otherwise it continues with its infection routine.
It also injects code into the "winlogon.exe" process.
Spreads Via…
File Infection
Virus:Win32/Gael.D infects .EXE files by appending itself to a target file, increasing the size of the file by 3666 bytes. It infects all .EXE files it finds in the system, including writable network shares.
Downloads and Executes Arbitrary Files
Virus:Win32/Gael.D attempts to download the following file:
File name: dl.exe
The file "dl.exe" is currently detected as TrojanDownloader:Win32/Gael.A.
Gael also attempts to connect to the following server:
Port:    54321
This connection may allow a remote attacker to control the infected machine and to download and execute other programs, including additional malware.
Analysis by Francis Allan Tan Seng


System Changes
The following system changes may indicate the presence of Virus:Win32/Gael.D:
  • Network traffic on TCP port 54321 with connection to IRC server
  • Increase in file size of infected files by 3666 bytes
  • Infected files fail during execution and have a recent modified date property


Alert level: Severe
First detected by definition:
Latest detected by definition: and higher
First detected on: Oct 07, 2008
This entry was first published on: May 28, 2008
This entry was updated on: Apr 17, 2011

This threat is also detected as:
  • Virus.Win32.Tenga.a (Kaspersky)
  • W32/Tenga-A (Sophos)
  • W32/Gael.worm.a (McAfee)
  • Tenga.a (v) (Sunbelt Software)
  • W32.Licum (Symantec)
  • PE_TENGA.A (Trend Micro)