Rootkit:W32/Small.LA is functionally a trojan with rootkit capabilities. It also has backdoor functionalities.This malicious program targets several online poker games. Small.LA is distributed from the website checkraised.com embedded in a Rakeback calculator application (RBCalc.exe). The main screen of the calculator program looks like:
When the trojan application RBCalc.exe is executed, it silently drops the following 4 files to windows system directory:
The dropper then executes utlsrv.exe, the main trojan file.When the main file is run, it installs the following registry lauchpoint:
- [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] "Comclg32" = "%system%\utlsrv.exe /Comclg32.dll"
After that, it monitors the running processes and injects the spying component, comclg32.dll, to following list of tasks:
The trojan main component also checks if the following processes are running on system:
- zone alarm security
If any of the above processes exist, the trojan quits execution.
The trojan's main file installs and loads the driver ndsdavsrv.sys, and uses it to hide its process and the registry launchpoint.
When the spying component comclg32.dll is initialized, it starts a keylogger and connects to a remote server. The server can instruct the backdoor to do any of the following tasks:
- Download and execute files
- Send application screenshots
- Shutdown the trojan
- Upload files
The backdoor also sends out sensitive information to a remote server, including keylogger database, computer name, and the username and password of the following online poker applications: