BKDR_KRIDEX.KA

July 09, 2013
 Analysis by: Alvin Bacani
 ALIASES:

W32/Cridex.NTO!tr (Fortinet)

 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: Yes

  • 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. It may be downloaded from remote sites by other malware.

  TECHNICAL DETAILS

File Size:

133,632 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Jul 2013

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.

It may be downloaded from remote site(s) by the following malware:

  • TROJ_PIDIEF.USR

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
KB{Random Numbers}.exe = "%Application Data%\KB{Random Numbers}.exe"

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.216.107:8080
  • http://{BLOCKED}.{BLOCKED}.234.138:8080
  • http://{BLOCKED}.{BLOCKED}.17.180:8080
  • http://{BLOCKED}.{BLOCKED}.219.226:8080
  • http://{BLOCKED}.{BLOCKED}.29.136:8080
  • http://{BLOCKED}.{BLOCKED}.5.195:8080
  • http://{BLOCKED}.{BLOCKED}.55.163:8080
  • http://{BLOCKED}.{BLOCKED}.23.100:8080
  • http://{BLOCKED}.{BLOCKED}.74.5:8080
  • http://{BLOCKED}.{BLOCKED}.18.120:8080
  • http://{BLOCKED}.{BLOCKED}.129.95:8080
  • http://{BLOCKED}.{BLOCKED}.66.2:8080
  • http://{BLOCKED}.{BLOCKED}.130.98:8080
  • http://{BLOCKED}.{BLOCKED}.135.227:8080
  • http://{BLOCKED}.{BLOCKED}.30.185:8080
  • http://{BLOCKED}.{BLOCKED}.30.185:8080

  SOLUTION

Minimum Scan Engine:

9.300

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

Remove the malware/grayware file that dropped/downloaded BKDR_KRIDEX.KA

    •  TROJ_PIDIEF.USR

Step 3

Scan your computer with your Trend Micro product and note files detected as BKDR_KRIDEX.KA

Step 4

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • KB{Random Numbers}.exe = "%Application Data%\KB{Random Numbers}.exe"

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_KRIDEX.KA. 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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