TrojanSpy.Win32.FORMBOOK.THDOEBC


 ALIASES:

Trojan:Win32/Formbook!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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

It terminates itself if it detects it is being run in a virtual environment.

  TECHNICAL DETAILS

File Size:

196,608 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Apr 2023

Payload:

Modifies system registry, Terminates processes, Gathers specific data, Drops files

Arrival Details

This Trojan Spy 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 Spy drops the following files:

  • %Program Files%\{random characters}\{random characters}.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • {Malware File Path}\{Malware File Name} {path}
  • {Spawned Process} /c del "{Malware File Path}\{Malware File Name}" → Delete itself
  • {Spawned Process} /c copy "{Malware File Path}\{Malware File Name}" "%Program Files%\{random characters}\{random characters}.exe" /V → Create copy of itself

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %Program Files%\{random characters}

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • {16 random characters derived from the username}

It injects codes into the following process(es):

  • {Malware File Path}\{Malware File Name} {path}
  • explorer.exe
  • Any of the following legitimate Windows applications: (Spawned by the hijacked explorer.exe)
    • systray.exe
    • dwm.exe
    • wuauclt.exe
    • control.exe
    • autoconv.exe
    • audiodg.exe
    • raserver.exe
    • svchost.exe
    • chkdsk.exe
    • lsm.exe
    • services.exe
    • msiexec.exe
    • wininit.exe
    • cscript.exe
    • nbtstat.exe
    • taskhost.exe
    • colorcpl.exe
    • explorer.exe
    • wscript.exe
    • wlanext.exe
    • autochk.exe
    • msg.exe
    • NAPSTAT.exe
    • spoolsv.exe
    • lsass.exe
    • rundll32.exe
    • msdt.exe
    • cmstp.exe
    • autofmt.exe
    • help.exe
    • rdpclip.exe
    • wuapp.exe
    • WWAHost.exe
    • ipconfig.exe
    • NETSTAT.exe
    • mstsc.exe
    • cmmon32.exe
    • netsh.exe
    • cmd.exe
  • {Targeted Applications}

It terminates itself if it finds the following processes in the affected system's memory:

  • vmwareuser.exe
  • vmwareservice.exe
  • vboxservice.exe
  • vboxtray.exe
  • sandboxiedcomlaunch.exe
  • sandboxierpcss.exe
  • procmon.exe
  • filemon.exe
  • wireshark.exe
  • netmon.exe
  • SharedIntApp.exe
  • vmtoolsd.exe
  • vmsrvc.exe
  • vmusrvc.exe
  • python.exe
  • perl.exe
  • regmon.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WindowsNT\CurrentVersion\Run
{random characters} = %Program Files%\{random characters}\{random characters}.exe

Information Theft

This Trojan Spy gathers the following data:

  • Username
  • OS Version and Product Name
  • OS Architecture
  • CRC32 of SID
  • Information from the following applications:
    • Browsers:
      • 360 Browser
      • Avant
      • Avast SafeZone Browser
      • Baidu
      • BlackHawk
      • Chrome
      • Citrio
      • Comodo Dragon
      • Comodo IceDragon
      • CoolNovo
      • Coowon
      • CyberFox
      • Deepnet
      • Dooble
      • Epic
      • Firefox
      • Internet Explorer
      • Iridium
      • KMeleon
      • Lunascape
      • Maxthon
      • Microsoft Edge
      • Midori
      • Mustang
      • Opera
      • Orbitum
      • PaleMoon
      • QTWeb
      • QupZilla
      • Safari
      • SeaMonkey
      • Sleipnir
      • Superbird
      • Torch
      • UC Browser
      • Vivaldi
      • Waterfox
      • Yandex
    • Mail Clients:
      • Barca
      • Foxmail
      • GMail
      • Incredimail
      • Microsoft Outlook
      • Mozilla Thunderbird
      • Opera Mail
    • FTP Client:
      • 3DFTP
    • Instant Messaging (IM) Applications:
      • ICQ Messenger
      • Pidgin
      • Skype
      • Trillian
      • Yahoo Messenger

Other Details

This Trojan Spy terminates itself if it detects it is being run in a virtual environment.

It does the following:

  • It terminates itself if the following DLL is loaded on its memory:
    • SbieDll.dll
  • It terminates itself if the following DLL loaded on its memory has the following strings in their filepath:
    • \cuckoo\
    • \sandcastle\
    • \aswsnx\
    • \sandbox\
    • \smpdir\
    • \samroot\
    • \avctestsuite\
  • It terminates itself if its filename has a length greater than or equal to 32 characters.
  • It looks for the following strings on HTTP requests:
    • pass
    • token
    • email
    • login
    • sign in
    • account
    • persistent

It terminates itself if any of the following user name(s) are found in the affected system:

  • cuckoo
  • cuckoo
  • sandbox-
  • nmsdbox-
  • xxxx-ox-
  • cwsx-
  • wilbert-sc
  • xpamast-sc

It does not proceed to its malicious routine if it detects that it is being debugged.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.364.03

FIRST VSAPI PATTERN DATE:

05 Apr 2023

VSAPI OPR PATTERN File:

18.365.00

VSAPI OPR PATTERN Date:

06 Apr 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    Troj.Win32.TRX.XXPE50FFF067

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

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_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Run
    • %Program Files%\{random characters}\{random characters}.exe

Step 6

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.  
  • %Program Files%\{random characters}\{random characters}.exe

Step 7

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Program Files%\{random characters}

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TrojanSpy.Win32.FORMBOOK.THDOEBC. 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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