BKDR_IRCBOT.CSK

 Analysis by: Mark Joseph Manahan

 ALIASES:

W32/IRCBot-based!Maximus (FProt), probably unknown NewHeur_PE virus (Eset)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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.

  TECHNICAL DETAILS

Ports:

TCP Port 443

File Size:

45,056 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

09 Mar 2013

Payload:

Connects to URLs/IPs

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:

  • evil1loldild0s

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
Wincpa = "{Malware Path and Filename}.exe"

Backdoor Routine

This backdoor connects to any of the following IRC server(s):

  • {BLOCKED}9.{BLOCKED}9.249.189

It joins any of the following IRC channel(s):

  • test3

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
  • [Speedtest] - check connection speed (rolotech-electronics.comuf.com, speedtest1.hivelocity.net, 68.11.12.242)
  • [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
  • [Get] Sends GET floods
  • [Post] Sends POST floods

Other Details

This backdoor uses the following credentials when accessing its IRC server:

  • USERNAME: zwin-{random}
  • PASSWORD: {BLOCKED}ation {BLOCKED}dos / {BLOCKED}dos

  SOLUTION

Minimum Scan Engine:

9.300

VSAPI OPR PATTERN File:

9.775.00

VSAPI OPR PATTERN Date:

09 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

Identify and terminate files detected as BKDR_IRCBOT.CSK

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Delete this registry value

[ Learn More ]

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
    • Wincpa = "{Malware Path and Filename}.exe"

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_IRCBOT.CSK. 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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