Analysis by: Joselyn Canuela
 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Worm may arrive bundled with malware packages as a malware component.

It exports functions used by other malware. It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: 5,579,776 bytes
File Type: DLL
Initial Samples Received Date: 12 May 2017

Arrival Details

This Worm may arrive bundled with malware packages as a malware component.

Other Details

This Worm exports functions used by other malware.

It requires its main component to successfully perform its intended routine.

It requires the existence of the following files to properly run:

  • C:\nyxksgcgcxfld\ngqylcsvczhgshqya
  • %Malware Path%\kvohVUQwzYXWEPyGeKJleoaMwyTAd.bmp

NOTES:

It consists of the following export calls:

  • UiirAJJSSSbbkbkS
    • It opens a mutex name as MbwovCtfuMbwovCtfu
    • It scans for a window name EfcRiEUQgXK
    • It drops a file %Malware Path%\IndexerVolumeGuid - encrypted file
    • It executes %Malware Path%\kvohVUQwzYXWEPyGeKJleoaMwyTAd.bmp - hidden
    • It opens an existing file: C:\nyxksgcgcxfld\ngqylcsvczhgshqya
  • bntlfmkwuynjd - function used to allocate memory
  • ekuuwealeqkbcvi - function used to compare string
  • fvbvzxynmjbl - function for string manipulation
  • glaundseckt
  • jvbzcejvneraoow
  • qkraoficliy
  • taagcrjfprr
    • It scans for a window name EfcRiEUQgXK and get the handle to its menu
    • It opens %Malware Path%\IndexerVolumeGuid and copy the content to a virtual memory location
    • It generates a beep sound
  • yqbedukiwocgr
    • It enumerate all entries in the property list of a window
    • It retrieves and identifies the code page

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.400.05
FIRST VSAPI PATTERN DATE: 12 May 2017
VSAPI OPR PATTERN File: 13.401.00
VSAPI OPR PATTERN Date: 13 May 2017

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %Malware Path%\IndexerVolumeGuid

Step 4

Scan your computer with your Trend Micro product to delete files detected as WORM_GAMARUE.YYOV. 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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