BKDR_IRCBOT.CBC
Microsoft: Backdoor:Win32/IRCbot.gen!K; Symantec: W32.IRCBot
Windows 2000, XP, Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This backdoor may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.
It adds registry entries to enable its automatic execution at every system startup.
It connects to Internet Relay Chat (IRC) servers.
TECHNICAL DETAILS
Arrival Details
This backdoor may be downloaded by other malware/grayware/spyware from remote sites.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This backdoor drops the following copies of itself into the affected system:
- %Windows%\svchost.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- fgzh9xe54j0
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\
Windows\CURRENTVERSION\RUN
sysdiag64.exe = %Windows%\svchost.exe
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
Windows\CURRENTVERSION\RUN
MicrosoftNAPC = %Windows%\svchost.exe
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
Windows\CURRENTVERSION\Policies\
Explorer\RUN
MicrosoftCorp = %Windows%\svchost.exe
Backdoor Routine
This backdoor opens the following ports:
- 6667
It connects to any of the following Internet Relay Chat (IRC) servers:
- xxxxxtsghxxxxx.info
It joins any of the following IRC channel(s):
- ##TsGh##
SOLUTION
Step 1
For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Identify and terminate files detected as BKDR_IRCBOT.CBC
- For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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
- sysdiag64.exe = %Windows%\svchost.exe
- sysdiag64.exe = %Windows%\svchost.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\RUN
- MicrosoftNAPC = %Windows%\svchost.exe
- MicrosoftNAPC = %Windows%\svchost.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Policies\Explorer\RUN
- MicrosoftCorp = %Windows%\svchost.exe
- MicrosoftCorp = %Windows%\svchost.exe
Step 4
Scan your computer with your Trend Micro product to delete files detected as BKDR_IRCBOT.CBC 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.
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