BKDR_FAKETM.XL

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor injects codes into the following process(es):

• explorer.exe

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MUmintry KRSteam = "%System%:SKRSteam.exe" (for versions other than Windows Vista/Windows 7)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MUmintry KRSteam = “%User Profile%\AppData\Roaming:SKRSteam.exe" (for Windows Vista/Windows 7 only)

Other Details

This backdoor connects to the following possibly malicious URL:

• {BLOCKED}w.{BLOCKED}arleft.com:443
• {BLOCKED}.{BLOCKED}.1.114:443

NOTES:

It drops a copy of itself to an alternate data stream (ADS) and saves it as follows:

• %User Profile%\AppData\Roaming KRSteam.exe (for Windows Vista/Windows 7 only with Admin Rights)
• %System% KRSteam.exe (for versions other than Windows Vista/Windows 7 with Admin Rights Privilege)

(Note: %User Profile% is the current user's profile folder, which is usually C:\Users\{user name} on Windows Vista and Windows 7, C:\Windows\Profiles\{user name} on Windows 98 and Windows ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, Windows XP, and Windows Server 2003. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and Windows ME, C:\WINNT\System32 on Windows NT and Windows 2000, or C:\Windows\System32 on Windows XP and Windows Server 2003.)