WORM_IRCBOT.AKZ

Malware type: Worm

Aliases: No Alias Found

In the wild: No

Destructive: No

Language: English

Platform: Windows 98, ME, NT, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

High

Distribution potential:

High

Infection Channel 1 : Propagates via network shares


Description: 

This worm may be dropped by other malware. It may be downloaded unknowingly by a user when visiting malicious Web sites.

It drops a copy of itself.

It creates registry entries to enable its automatic execution at every system startup.

It disables the DCOM protocol. It restricts anonymous access to the affected system.

For additional information about this threat, see:

Description created: Jan. 25, 2008 2:38:07 PM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 53,248 Bytes

Initial samples received on: Jan 21, 2008

Details:

Arrival Details

This worm may be dropped by other malware. It may be downloaded unknowingly by a user when visiting malicious Web sites.

Installation

This worm drops the following copy of itself:

  • %System%\mdm.exe

(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 Techniques

This worm creates the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
Run
Windows Networking Monitoring = "%System%\mdm.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
Run
Windows Networking Monitoring = "%System%\mdm.exe"

Other System Modifications

This worm modifies the following registry entry to disable the DCOM protocol:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
EnableDCOM = "N"

(Note: The default value data for the said registry entry is Y.)

It modifies the following registry entry to restrict anonymous access to the affected system:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous = "1"

(Note: The default value data for the said registry entry is 0.)

Download Routine

This worm accesses the following Web site to download a file which is a possible updated version of itself:

  • http://wow.{BLOCKED}rc.us/mixit.exe

The said URL is inaccessible as of this writing.

Backdoor Capabilities

This worm connects to the Internet Relay Chat (IRC) server x.blackcrew.us. It joins the IRC channel #!MMT!.

It opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user can execute commands on the affected system. The commands that may be executed are the following:

  • Create or delete network shares
  • Create random nickname
  • Join or leave IRC channel
  • List processes
  • Open a remote shell
  • Perform FTP operations
  • Terminate processes
  • Uses random ports

These routines give the remote malicious user virtual control over the affected system, thereby compromising system security.

Propagation via Network Shares

This worm propagates via network shares by dropping a copy of itself into the shared folder IPC$.

Affected Platforms

This worm runs on Windows 98, ME, NT, 2000, XP, and Server 2003.


SOLUTION


Minimum scan engine version needed: 8.300

Pattern file needed: 4.957.00

Pattern release date: Jan 22, 2008


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

Important Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected computers.

Users running other Windows versions can proceed with the succeeding solution set(s).

Restarting in Safe Mode

This malware has characteristics that require the computer to be restarted in safe mode. Go to this page for instructions on how to restart your computer in safe mode.

Removing Autostart Entries from the Registry

This solution deletes/modifies registry keys/entries added/modified by this malware. Before performing the steps below, make sure you know how to back up the registry and how to restore it if a problem occurs. Refer to this Microsoft article for more information about modifying your computer's registry.

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>
    Run
  3. In the right panel, locate and delete the entry:
    Windows Networking Monitoring = "%System%\mdm.exe"
    (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.)
  4. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>
    Run
  5. In the right panel, locate and delete the entry:
    Windows Networking Monitoring = "%System%\mdm.exe"
  6. Close Registry Editor.

This malware modifies RestrictAnonymous registry entry to a certain value. To restore this entry to its original value, perform the steps below:

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>System>CurrentControlSet>
    Control>Lsa
  3. In the right panel, locate the entry:
    Restrictanonymous = "1"
  4. Right-click on the value name and choose Modify. Change the value data of this entry according to your preference. Note that this entry does not exist in the registry by default. Refer to the following Microsoft articles as guides in editing the RestrictAnonymous registry:
  5. Close Registry Editor.

This malware modifies EnableDCOM to a certain value. To restore this entry to its original value, perform the steps below:

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Ole
  3. In the right panel, locate the entry:
    EnableDCOM = "N"
  4. Right-click on the value name and choose Modify. Change the value data of this entry to:
    Y
  5. Close Registry Editor.

Running Trend Micro Antivirus

If you are currently running in safe mode, please restart your computer normally before performing the following solution.

Scan your computer with Trend Micro antivirus and delete files detected as WORM_IRCBOT.AKZ. To do this, Trend Micro customers must download the latest virus pattern file and scan their computer. Other Internet users can use HouseCall, the Trend Micro online virus scanner.




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