Windows 2000, Windows XP, Windows Server 2003
This worm arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
81,408 bytes
EXE
Yes
24 Jul 2011
Arrival Details
This worm arrives via removable drives.
It 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 worm drops the following copies of itself into the affected system:
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
MicrosoftCorp = "%System%\msnrmgs.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MicrosoftNAPC = "%System%\msnrmgs.exe"
Backdoor Routine
This worm connects to the following URL(s) to send and receive commands from a remote malicious user:
8.900
8.308.03
24 Jul 2011
8.309.00
24 Jul 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 2
Identify and terminate files detected as WORM_IRCBOT.JMZ
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.
Step 4
Scan your computer with your Trend Micro product to delete files detected as WORM_IRCBOT.JMZ. 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.