Backdoor:W32/Agent.CTH

Classification

Type:Backdoor

Summary

Backdoor:W32/Agent.CTH is a backdoor that can steal information. Stolen information is sent to a collection site using an HTTP POST command.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.

Technical Details

Upon execution, this malware drops the following files:

%windir%\system32\aspimgr.exe
%windir%\s32.txt
%windir%\ws386.ini

The files s32.txt and ws386.ini are logs.As part of its autostart mechanism, it installs itself as a system service.

HKLM\SYSTEM\ControlSet001\Services\aspimgr\ ImagePath = 'C:\WINDOWS\System32\aspimgr.exe'
HKLM\SYSTEM\ControlSet001\Services\aspimgr\ DisplayName = 'Microsoft ASPI Manager'

It also creates the following registry entry:

HKLM\SOFTWARE\Microsoft\Sft\ {5BB68E6F-37D5-468A-992B-F34CD2A191EA}

It checks for Internet connectivity by attempting to connect to the following sites:

www.yahoo.com
www.web.de

This malware can steal information such as:

Cute FTP client username/passwords
Inetcomm server username/passwords
IPswitch WS_FTP client username/passwords
Outlook account username/passwords
Protected storage username/passwords
The Bat! username/passwords

Stolen information is sent to a collection site using an HTTP POST command.It also collects email addresses but ignores addresses with the following strings: