WORM_KUVAA.A

May 07, 2013
 Analysis by: Anthony Joe Melgarejo
 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: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

This worm may be downloaded from remote sites by other malware.

  TECHNICAL DETAILS

File Size:

32,768 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

02 May 2013

Payload:

Downloads files

Arrival Details

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

  • BKDR_LIFTOH.DLF

Download Routine

This worm downloads updated copies of itself from the following websites:

  • http://f.{BLOCKED}adio.su/f/image.png

Other Details

This worm checks for the presence of the following process(es):

  • webkit2webprocess.exe
  • opera.exe
  • iexplore.exe
  • firefox.exe
  • facebookmessenger.exe
  • chrome.exe

NOTES:

Once it finds the browser processes mentioned, it will look for the c_user and xs cookies to bypass Facebook authentication.

Then, it will utilize a Facebook Anti-CSRF token, fb_dtsg, to spam messages containing a sentence and the link to the updated copy of itself.

The sentence is written in 11 different languages:

English
i cant believe i still have this picture

German
kennst du das foto schon?

Dutch
ken je dat foto nog?

Czech
podivejte se na mou fotku

Danish
ser pa dette billede

Spanish
mira como saliste en esta foto

Finnish
katso tata kuvaa

Norwegian
se pa dette bildet

Swedish
titta pa denna bild

French
c'est la photo la plus marrante!

Italian
la foto e grandiosa!

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.892.04

FIRST VSAPI PATTERN DATE:

02 May 2013

VSAPI OPR PATTERN File:

9.893.00

VSAPI OPR PATTERN Date:

03 May 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 WORM_KUVAA.A

[ 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

Remove the malware/grayware file that dropped/downloaded WORM_KUVAA.A

Step 4

Scan your computer with your Trend Micro product to delete files detected as WORM_KUVAA.A. 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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