Modified by: Vincent Martin Hermosura
ALIASES:

Trojan-Dropper.Win32.Dorifel.alzp (Kaspersky), TrojanDropper:Win32/Cutwail (Microsoft), RDN/Generic Dropper!va (Mcafee), Troj/Cutwail-BH (Sophos), Trojan.Win32.Generic!BT (Sunbelt), TR/Drop.Cutwail.30 (Antivir), Gen:Variant.Kazy.430851 (Bitdefender), W32/Dorifel.ALZP!tr (Fortinet), Trojan.Win32.Cutwail (Ikarus), a variant of Win32/Kryptik.CIPN trojan (Esset)

 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

This Trojan 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

File Size: 93,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 Aug 2014

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system:

  • %User Profile%\{random characters}.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random charcters} = "%User Profile%\{random characters}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
AppManagement = "{hex values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
{random characters}zap = "{hex values}"

NOTES:

This malware randomly connects to the following websites:

  • 101hotel.is
  • 4joo.com
  • abdg.com
  • aclumich.org
  • acmf.com.au
  • acrylabs.com
  • agaman.net
  • aig-co.com
  • alten.co.uk
  • aqarea.com
  • araf.de
  • atb-lit.com
  • atkom.ru
  • banijya.com
  • bars-dek.com
  • boyar.com.tr
  • buydebt.net
  • chzko.ru
  • cocif.com
  • comiteaz.com
  • comuval.es
  • darinne.ro
  • deltains.org
  • dendai.com
  • dicre.com
  • djvjp.com
  • dreamhop.com
  • dzm.cz
  • ecss.com.au
  • elmets.com
  • eretz.org
  • errigal.com
  • etipage.com
  • famdra.co.za
  • fatih.com.tr
  • from30ty.com
  • golfprop.com
  • hanakume.com
  • hbymail.com
  • heffeter.com
  • helinc.com
  • hosse.ch
  • hsbj.org
  • idecom.it
  • iihed.org
  • inforhard.pt
  • interdisc.de
  • joesabia.com
  • jojome.net
  • k-kogaku.com
  • k-sosin.com
  • kiwicr.com
  • ksa2.com
  • ktavtam.com
  • ladtron.com
  • lmpa.org.au
  • lpmcom.pt
  • madkom.pl
  • mbwswim.com
  • mediates.com
  • milfa.pt
  • mjol.co.uk
  • monteux.fr
  • multip.hu
  • music.us
  • mvf-rlm.com
  • mygolf1.com
  • ncsl.cc
  • nmtdie.com
  • noriko7.com
  • nwpolice.org
  • ommetals.com
  • onshodo.net
  • oozkranj.com
  • plcsi.net
  • plei.net
  • pmas.org
  • ppic.com
  • radeton.cz
  • radieserl.de
  • rdplf.org
  • rodesfer.com
  • sennema.com
  • sonat.de
  • sonowest.com
  • soumen.co.jp
  • stermedia.pl
  • stnic.co.uk
  • tamara.net
  • tip-top.cz
  • torlys.com
  • uvasindia.in
  • varinex.hu
  • viadon.com
  • vimarc.com
  • vipmel.net
  • x96.com
  • xlp.org.uk
  • zeltea.ru
  • zyrion.com

  SOLUTION

Minimum Scan Engine: 9.700

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

Restart in Safe Mode

[ Learn More ]

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
    • AppManagement = {hex values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • {random characters}zap = {hex values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random charcters} = "%User Profile%\{random characters}.exe"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CUTWAIL.YBM. 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 6

The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.

  • "%User Profile%\{random characters}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • {random characters}zap = {hex values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random charcters} = "%User Profile%\{random characters}.exe"


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