This trojan-spy takes advantage of a critical vulnerability to harvest sensitive, personal information from an infected machine. The information is then forwarded to a remote server for further, malicious use.
This trojan is reportedly installed on a Windows system by exploiting a critical vulnerability in the server service, which involves improper handling of specially crafted remote procedure call (RPC) requests. Successfully exploiting this vulnerability may provide an attacker complete control of an infected system. Further details of the vulnerability are available in the Microsoft Security Bulletin MS08-067.
On execution, the trojan-spy drops a DLL component, which is also detected as Trojan-Spy:W32/Gimmiv.A, as:
- [System Folder]\wbem\sysmgr.dll
The DLL is injected into svchost.exe. The main executable file will then delete itself.
As part of its routine for connecting to a remote server, the trojan will take into account both the operating system version and the presence of any security applications in the system. The trojan checks for the following antivirus programs:
- OneCare Protection
The trojan then attempts to connect to:
The two parameters 'abc=' and 'def=' are determined by the antivirus program and the operating system version, respectively. For example, if avp.exe is installed on an infected machine that runs Windows XP, then abc=1 and def=2.
The trojan then harvests the following information from the infected machine:
- MSN Credentials
- Outlook Express Credentials
- Protected Storage Information
- Patches Installed
- Browser Information
- Username (web browsing)
The harvested information is encrypted using Advanced Encryption Standard (AES) and is sent to the remote server.
The DLL component is registered as a service by adding registry entries.