Trojan.Downbot
Trojan.Downbot is a computer Trojan that will download more threats on the already infected computer. The Trojan focuses on several known organizations like private companies and government agencies worldwide. The objective of the attack as foreseen by security expert is to steal sensitive information from these organizations. Trojan.Downbot will arrive on target computer by a drive-by download method.
Damage Level: Medium
Systems Affected: Windows 9x, 2000, XP, Windows Vista
Characteristics
Once it is run, Trojan.Downbot will drop harmful files and make several changes on computer settings. The attacks are composing of three levels – email spamming, computer infection and thorough backdoor usage. The last level of using a backdoor allows the attackers to take full control of the infected system.
When the Trojan is loaded on the PC, it may perform other tasks including the following:
- Download more files from a remote server.
- Deactivate the Trojan for specified time.
- Open a backdoor and connect to specified IP address.
- Send and receive commands from a remote attacker.
Distribution
As of this writing, only known channel used by Trojan.Downbot to spread a copy is through email campaign. The message of this email contains a link that points to an executable file or it may directly carry the file as attachment.
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows\"load" = "%Temp%\cisvc.exe"Associated Files and Folders:
%Temp%\cisvc.exe
How to Remove Trojan.Downbot
1. Temporarily Disable System Restore (Windows Me/XP). [how to]
2. To be able to identify even the most recent variant of Trojan.Downbot, open your antivirus application and update the virus definition file.
3. Start Windows in Safe Mode with Networking.
- From a power-off state, turn on the computer and press F8 on your keyboard repeatedly.
- Your computer will display Windows Advanced Boot Options menu. Please select Safe Mode with Networking.
- The system will boot Windows loading only necessary drivers and files.
4. Open your antivirus program and run a full system scan. After the scan, delete all infected items. If unable to delete, better place them in quarantine. Once the scan is complete, please proceed with the next step.
Scan with Norton Power Eraser:
Additional virus removal tool provides deep scanning technology to eliminate other threats not detected by a normal virus scan. Use this tool with extra caution.
5. Go to NPE web page and download the tool.
6. Once the download completes, double click on the file NPE.exe to run the program.
7. It will prompt for End User License Agreement, click on Accept to continue.
8. On NPE main window, click on Scan. Then select Exclude Rootkit Scan. Click on Continue to proceed.
9. Virus scanning may take some time. After running the scan, NPE will display the scan result.
Important! If there are any detected threats under Suspicious, remove the check mark. Only threats in Detected category are necessary to remove at this point. Make sure that you mark the Create System Restore Point before proceeding with the fix.
10. Now click on Fix to start removing the threats including Trojan.Downbot remnants if there are any.
11. When done, Norton Power Eraser will restart the computer. Then after a reboot, it will initialize and display the eliminated threats.
12. You may now close Norton Power Eraser.