BAT_COSMU.MC
Trojan-Downloader.BAT.Agent.hk (Kaspersky); Bat/sdel (Mcafee)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This malicious batch file attempts to install other possibly malicious files by connecting to an FTP site. It logs into the said FTP using a predefined password. It then goes to the directory in the FTP named bedniagi and attempts to download and execute two files. However, as of this writing, it fails to log into the FTP successfully due to wrong credentials.
It also obtains the IP configuration of the affected machine via the shell command "ipconfig /all".
This Trojan may be dropped by other malware.
TECHNICAL DETAILS
1,376 bytes
BAT
No
24 Aug 2011
Connects to FTP sites
Arrival Details
This Trojan may be dropped by the following malware:
- WORM_COSMU.MC
Autostart Technique
This Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
registry = "%System%\contrvs.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
registry = "%System%\spolsv.exe"
NOTES:
This malicious batch file attempts to install other possibly malicious files by connecting to the FTP site ftp.{BLOCKED}a2009.sa.funpic.de . It logs into the said FTP using a predefined password. It then goes to the directory in the FTP named bedniagi and attempts to download and execute two files which are saved as follows:
- %System%\contrvs.exe
- %System%\spolsv.exe
However, as of this writing, it fails to log into the FTP successfully due to wrong credentials.
It also obtains the IP configuration of the affected machine via the shell command "ipconfig /all". It logs the acquired information as %Current%\{computer name}.txt. This log file, along with the FTP download routine logs, is saved to another file, %Current%\upl.txt, which is uploaded to the FTP.
After execution, it deletes itself and the following log files:
- %Current%\{computer name}.txt
- %Current%\upl.txt
SOLUTION
8.900
8.376.06
24 Aug 2011
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 3
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- registry = "%System%\contrvs.exe"
- registry = "%System%\contrvs.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- registry = "%System%\spolsv.exe"
- registry = "%System%\spolsv.exe"
Step 4
Scan your computer with your Trend Micro product to delete files detected as BAT_COSMU.MC. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Did this description help? Tell us how we did.