BKDR_IRCBOT.FAG
Worm:Win32/Autorun.AFV (Microsoft), Win32/AutoRun.KS worm (ESET), Trojan.Win32.Jorik.IRCbot.oki (Kaspersky)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It listens on ports. It may also connect to Internet Relay Chat (IRC) servers and receive commands from a remote user.
It performs denial of service (DoS) attacks on affected systems using specific flooding method(s).
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Varies
EXE
Yes
23 Jul 2012
Connects to URLs/IPs
Arrival Details
This Trojan 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 Trojan drops the following files:
- %User Profile%\Application Data\new.bin
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It drops the following copies of itself into the affected system:
- %User Profile%\Application Data\RECYCLER\logon.exe
- %User Profile%\Application Data\winlogon.scr
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It injects itself into the following processes running in the affected system's memory:
- explorer.exe
It creates the following folders:
- %User Profile%\Application Data\RECYCLER
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- bvjfdusnc
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Remote Shell Manager = "%User Profile%\Application Data\RECYCLER\logon.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Protect Manager = "%User Profile%\Application Data\winlogon.scr"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = ".exe;.scr;"
Backdoor Routine
This Trojan listens on the following ports:
- 7081
It connects to any of the following IRC server(s):
- d.{BLOCKED}book.com
It may also connect to Internet Relay Chat (IRC) servers and receive commands from a remote user.
Denial of Service (DoS) Attack
This Trojan performs denial of service (DoS) attacks on affected systems using the following flooding method(s):
- SYN flood
- UDP flood
Download Routine
This Trojan accesses the following websites to download files:
- http://{BLOCKED}.{BLOCKED}.246.148/july/1888.exe
As of this writing, the said sites are inaccessible.
NOTES:
The remote command received may contain its propagation routine through IRC.
SOLUTION
9.200
9.294.03
30 Jul 2012
9.295.00
31 Jul 2012
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
Restart in Safe Mode
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
- Remote Shell Manager = "%User Profile%\Application Data\RECYCLER\logon.exe"
- Remote Shell Manager = "%User Profile%\Application Data\RECYCLER\logon.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Protect Manager = "%User Profile%\Application Data\winlogon.scr"
- Windows Protect Manager = "%User Profile%\Application Data\winlogon.scr"
Step 4
Delete this registry key
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\Policies
- Associations
- Associations
Step 5
Search and delete these folders
- %User Profile%\Application Data\RECYCLER
Step 6
Search and delete this file
- %User Profile%\Application Data\new.bin
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_IRCBOT.FAG. 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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