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.
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:
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
The following system changes may indicate the presence of Virus:Win32/Gael.D:
Network traffic on TCP port 54321 with connection to IRC server vx9.users.freebsd.at
Increase in file size of infected files by 3666 bytes
Infected files fail during execution and have a recent modified date property