Small.QP copies itself to the Windows folder and attempts to download and install other malware to the system.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Upon execution, this malware creates the mutex _Win_Loader_ to ensure that only one instance of itself is running in memory.Additionally, it drops the following files in the affected system:
- %windir%\winlogon32.exe - A copy of itself (Detected as Trojan-Dropper.Win32.Small.qp)
- %windir%\winlogon32.dll - Another malware file (Detected as Trojan-Downloader.Win32.Small.anj)
- %windir%\prefoct.dat - An empty file
As a stealth mechanism, it loads the dropped DLL, winlogon32.dll, under the legitimate process: lsass.exe.Trojan-Downloader.Win32.Small.anj, on the other hand, creates the mutex _Win_Loader__Win_Loader_.This malware attempts to connect to the following web sites to possibly download other malicious components:
- http://www.max-stats.com/l/[REMOVED].php?i=21 Data downloaded is saved in the file, %windir%\prefoct.dat
- http://www.teen4-sex.com/[REMOVED].dat Data downloaded is saved in the file, %wndir%\_tmp0232.exe
Small.QP then executes the downloaded file, _tmp0232.exe. Note: Both download sites are unavailable at the time of writing.There are additional details on Small.QP on F-Secure's Weblog.