BKDR_IRCBOT.CSS
VirTool:Win32/CeeInject.gen!A, Trojan:Win32/Ircbrute(Microsoft), W32.Pilleuz(Norton), W32/Dorkbot.AS!tr(Fortinet), a variant of Win32/Injector.AEDM trojan(Eset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It joins an Internet Relay Chat (IRC) channel.
TECHNICAL DETAILS
118,329 bytes
EXE
Yes
30 Mar 2013
Connects to URLs/IPs, Compromises system security
Arrival Details
This backdoor 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 backdoor adds the following mutexes to ensure that only one of its copies runs at any one time:
- ev1l1lod1ld0s
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windongs = "{malware path}\{malware file name}.exe"
Backdoor Routine
This backdoor connects to any of the following IRC server(s):
- {BLOCKED}n.{BLOCKED}s.cat
It joins any of the following Internet Relay Chat (IRC) channels:
- {BLOCKED}5
It accesses a remote Internet Relay Chat (IRC) server where it receives the following commands from a remote malicious user:
- [Quit] - Terminate itself
- [Help] - Print Commands
- [Version] - Print Version
- [Exec] - Executes shell command
- [DLE] - Downloads and execute arbitrary file
- [UDP] - Starts UDP Flooding
- [OpenURL] - Opens a URL using a hidden browser
- [SYN] - Sends a SYN Flood
- [Stop] - Stops a spcific command
- [Get] - Sends GET floods
- [Post] Sends POST floods
- [Speedtest] - check connection speed (rolotech-electronics.comuf.com, speedtest1.hivelocity.net, 68.11.12.242)
Other Details
This backdoor uses the following credentials when accessing its IRC server:
- USERNAME: ImGay
- NICK: zwin-{random}
SOLUTION
9.300
9.826.01
30 Mar 2013
9.827.00
31 Mar 2013
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windongs = "{malware path}\{malware file name}.exe"
- Windongs = "{malware path}\{malware file name}.exe"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_IRCBOT.CSS. 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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