WORM_IRCBOT.BZJ
Windows 2000, Windows XP, Windows Server 2003

Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
It receives commands from a remote malicious user via IRC. These commands are executed on the affected system. However, as of this writing, the said servers are inaccessible.
This worm arrives via removable drives.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It connects to Internet Relay Chat (IRC) servers.
TECHNICAL DETAILS
Arrival Details
This worm arrives via removable drives.
Installation
This worm drops the following copies of itself into the affected system:
- {Drive:}\MSN\D\Mic.exe
It injects itself into the following processes running in the affected system's memory:
- Explorer.exe
It creates the following folders:
- {Drive:}\MSN
- {Drive:}\MSN\D
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{91BPF6G1-4ELN-6M2E-BBZ9-4020406080a0}
StubPath = {Drive:}\MSN\D\Mic.exe
Propagation
This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[autorun]
open=MSN\D\Mic.exe
;{garbage}
action=Open folder to view files
shell\open=Open
shell\open\command=MSN\D\Mic.exe
shell\open\default=1
Backdoor Routine
This worm connects to any of the following Internet Relay Chat (IRC) servers:
- {BLOCKED}r.{BLOCKED}ils.net
- {BLOCKED}r.{BLOCKED}rk.biz
Other Details
This worm does the following:
- It receives commands from a remote malicious user via IRC. These commands are executed on the affected system. However, as of this writing, the said servers are inaccessible.
SOLUTION
Step 1
Restart in Safe Mode
Step 2
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\
- {91BPF6G1-4ELN-6M2E-BBZ9-4020406080a0}
- {91BPF6G1-4ELN-6M2E-BBZ9-4020406080a0}
Step 3
Search and delete these folders
{Drive:}\MSN
Step 4
Search and delete AUTORUN.INF files created by WORM_IRCBOT.BZJ that contain these strings
open=MSN\D\Mic.exe
;{garbage}
action=Open folder to view files
shell\open=Open
shell\open\command=MSN\D\Mic.exe
shell\open\default=1
Step 5
Search and delete these files
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_IRCBOT.BZJ. 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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