RANSOM_ABCLOCKER.A

 Analysis by: Rheniel Rhay Ramos

 ALIASES:

Trojan-Ransom.MSIL.Agent.gly (Kaspersky); Generic.Ransom.CloudSword.35F9E529 (Bitdefender); Ransom:Win32/ABCLocker.A!rsm (Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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

It encrypts files with specific file extensions. It encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

49,152 bytes

File Type:

EXE

Initial Samples Received Date:

25 Jul 2017

Payload:

Encrypts files

Arrival Details

This Ransomware 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 Ransomware drops the following copies of itself into the affected system and executes them:

  • %User Profile%\{MD5 hash of UUID}\Windows Update.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.)

It adds the following processes:

  • cmd.exe "bcdedit /set {default} recoveryenabled No" -> disable system recovery
  • cmd.exe "bcdedit /set {default} bootstatuspolicy ignoreallfailures" -> ignores all failures when booting
  • cmd.exe "netsh.exe Firewall set opmode disable" -> disables the firewall
  • %Windows%\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe “/logfile= /LogToConsole=false /U "%User Profile%\{MD5 hash of UUID}\Windows Update.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.)

It creates the following folders:

  • %User Profile%\{MD5 hash of UUID}

(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 Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{MD5 hash of UUID} = “%User Profile%\{MD5 hash of UUID}\Windows Update.exe”

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\{MD5 hash of UUID}\
FILE
{filename} = "{encrypted key}"
Where {filename} could be one of the following name of files encrypted by the malware

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows NT\SystemRestore
DisableSR = "1"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = "1"

(Note: The default value data of the said registry entry is "0".)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Defender = "{any data}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\{FD6905CE-952F-41F1-9A6F-135D9C6622CC}

Other Details

This Ransomware does the following:

  • It enumerates and encrypts files found in all logical drives.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .001
  • .1cd
  • .3fr
  • .3gp
  • .7z
  • .DayZProfile
  • .ac3
  • .acc
  • .accdb
  • .ai
  • .ape
  • .apk
  • .arch00
  • .arw
  • .asp
  • .asset
  • .avi
  • .bak
  • .bar
  • .bay
  • .bc6
  • .bc7
  • .big
  • .bik
  • .bkf
  • .bkp
  • .blob
  • .bmp
  • .bsa
  • .bson
  • .cas
  • .cdr
  • .cer
  • .cfr
  • .cpp
  • .cr2
  • .crt
  • .crw
  • .cs
  • .css
  • .csv
  • .d3dbsp
  • .das
  • .dat
  • .dazip
  • .db
  • .db0
  • .dbf
  • .dbfv
  • .dcr
  • .der
  • .desc
  • .divx
  • .djvu
  • .dmp
  • .dng
  • .doc
  • .docm
  • .docx
  • .dwg
  • .dxf
  • .dxg
  • .epk
  • .eps
  • .epub
  • .erf
  • .esm
  • .exif
  • .ff
  • .flac
  • .flv
  • .forge
  • .fos
  • .fpk
  • .fsh
  • .gdb
  • .gho
  • .gif
  • .gzip
  • .h
  • .hkdb
  • .hkx
  • .hplg
  • .htm
  • .html
  • .hvpl
  • .ibank
  • .icxs
  • .ifo
  • .indd
  • .iso
  • .itdb
  • .itl
  • .itm
  • .iwd
  • .iwi
  • .java
  • .jfif
  • .jpeg
  • .jpg
  • .js
  • .jsp
  • .kdb
  • .kdc
  • .kf
  • .kwm
  • .layout
  • .lbf
  • .litemod
  • .lrf
  • .ltx
  • .lvl
  • .m2
  • .m2v
  • .m3u
  • .m4a
  • .map
  • .max
  • .mcgame
  • .mcmeta
  • .md
  • .mdb
  • .mdbackup
  • .mddata
  • .mdf
  • .mef
  • .menu
  • .mkv
  • .mlx
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mpqge
  • .mrw
  • .mrwref
  • .myd
  • .ncf
  • .nef
  • .nrw
  • .ntl
  • .odb
  • .odc
  • .odm
  • .odp
  • .ods
  • .odt
  • .orf
  • .p12
  • .p7b
  • .p7c
  • .pak
  • .pdd
  • .pdf
  • .pef
  • .pem
  • .pfx
  • .php
  • .pkpass
  • .png
  • .pps
  • .ppt
  • .pptm
  • .pptx
  • .psd
  • .psk
  • .pst
  • .ptx
  • .pwm
  • .py
  • .qbb
  • .qbw
  • .qdf
  • .qic
  • .r3d
  • .raf
  • .rar
  • .raw
  • .rb
  • .rdf
  • .re4
  • .rgss3a
  • .rim
  • .rofl
  • .rtf
  • .rw2
  • .rwl
  • .sav
  • .sb
  • .sc2save
  • .sid
  • .sidd
  • .sidn
  • .sie
  • .sis
  • .slm
  • .snx
  • .sql
  • .sqlite
  • .sr2
  • .srf
  • .srw
  • .sum
  • .svg
  • .syncdb
  • .t12
  • .t13
  • .tar
  • .tax
  • .tif
  • .tor
  • .torrent
  • .txt
  • .unity3d
  • .upk
  • .vdf
  • .vfs0
  • .vob
  • .vpk
  • .vpp_pc
  • .vtf
  • .w3x
  • .wav
  • .wb2
  • .wma
  • .wmo
  • .wmv
  • .wotreplay
  • .wpd
  • .wps
  • .x3f
  • .xf
  • .xlk
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xml
  • .xxx
  • .zip
  • .ztmp

It encrypts files found in the following folders:

  • %User Profile%\Desktop
  • %User Profile%\Documents
  • %User Profile%\Music
  • %User Profile%\Pictures
  • %User Profile%\Videos

(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.)

It avoids encrypting files with the following strings in their file path:

  • 360safe
  • 360 Internet Security
  • 360Chrome
  • Total Security
  • Internet Explorer
  • Chrome
  • QQPCMgr
  • Sogou
  • Firefox
  • Safari
  • Opera
  • Kaspersky
  • Rising
  • UCbrowser
  • maxthon

It avoids encrypting files found in the following folders:

  • %Windows%

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

It renames encrypted files using the following names:

  • {Original filename Without Extension}

It drops the following file(s) as ransom note:

  • %User Profile%\Desktop\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Documents\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Music\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Pictures\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Videos\OPEN_TO_UNLOCK_YOUR_FILES.html

(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.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.558.07

FIRST VSAPI PATTERN DATE:

25 Jul 2017

VSAPI OPR PATTERN File:

13.559.00

VSAPI OPR PATTERN Date:

26 Jul 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

Identify and terminate files detected as RANSOM_ABCLOCKER.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 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\{MD5 hash of UUID}\FILE
    • {filename} = “{encrypted key}”
      Where {filename} could be one of the following name of files encrypted by the malware
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore
    • DisableSR = “1”

Step 5

Restore this modified 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\Windows\CurrentVersion\Policies\System
    • From: EnableLUA = “1”
      To: EnableLUA = “0”

Step 6

Search and delete these folders

[ 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.
  • %User Profile%\{MD5 hash of UUID}

Step 7

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.  
  • %User Profile%\Desktop\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Documents\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Music\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Pictures\OPEN_TO_UNLOCK_YOUR_FILES.html
  • %User Profile%\Videos\OPEN_TO_UNLOCK_YOUR_FILES.html

Step 8

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

Step 9

Restore encrypted files from backup.

NOTES:

Do this as Step 10 of the solution process:

Enable Windows Recovery Option and Enable Firewall

1. Run cmd.exe as administrator

2. Type "bcdedit /set {default} recoveryenabled Yes", then press Enter

3. Type "bcdedit /set {default} bootstatuspolicy displayallfailures", then press Enter.

4. Type "netsh.exe Firewall set opmode enable", then press Enter.


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