Ransom.Win32.STOP.GE
UDS:DangerousObject.Multi.Generic (KASPERSKY)
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 drops files as ransom note.
TECHNICAL DETAILS
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 files:
- %System Root%\SystemID\PersonalID.txt
- %ProgramData%\{Random Numbers} → Delete Afterwards
- %AppDataLocal%\bowsakkdestx.txt → Delete Afterwards
- %Temporary Internet Files%\Content.IE5\YEFGVF95\build2.exe → Delete Afterwards
- %Temporary Internet Files%\Content.IE5\YEFGVF95\116_203_9_69.txt
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista, 7 and 2008(64-bit), or C:\Users\{user name}\AppData\Local\Microsoft\Windows\INetCache on Windows 8, 8.1, 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- icalcs "%AppDataLocal%\{GUID}" /deny *S-1-1-0:(OI)(CI)(DE,DC)
- %AppDataLocal%\{GUID}\build2.exe
- %AppDataLocal%\{GUID}\build3.exe
- %System%\cmd.exe" /c timeout /t 6 & del /f /q "%AppDataLocal%\{GUID}build2.exe" & exit
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
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
SysHelper = %AppDataLocal%\{GUID}\{Malware Filename}.exe" --AutoStart
Download Routine
This Ransomware accesses the following websites to download files:
- http://{BLOCKED}.{BLOCKED}.9.69/get.zip
- http://{BLOCKED}is.com/test1/get.php?pid={hash}&first=true
- http://{BLOCKED}y.top/dl/build2.exe$run
- http://{BLOCKED}is.com/files/1/build3.exe$run
- http://{BLOCKED}.{BLOCKED}.9.69/19
It saves the files it downloads using the following names:
- %AppDataLocal%\{GUID}\build2.exe
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Information Theft
This Ransomware gathers the following data:
- IP Address
- MAC Address
- Computer Name
- User Name
Other Details
This Ransomware connects to the following URL(s) to get the affected system's IP address:
- https://{BLOCKED}i.{BLOCKED}p.ua/geo.json
- It terminates and deletes itself on the affected system if the return of the IP address location is any of the following:
- RU (Russia)
- BY (Belarus)
- UA (Ukraine)
- AZ (Azerbaijan)
- AM (Armenia)
- TJ (Tajikistan)
- KZ (Kazakhstan)
- KG (Kyrgyzstan)
- UZ (Uzbekistan)
- SY (Syrian Arab Republic)
It accepts the following parameters:
- --Admin → runs the malware as admin
- --AutoStart → executes using autorun registry keys
- IsAutoStart/IsNotAutoStart → executes malware as an autostart or not
- IsTask/IsNotTask → executes malware as a task or not
- --ForNetRes {argument/s from URL}
- --Service {PID of parent malware} {argument/s from URL}
It adds the following scheduled tasks:
- Task Name: Time Trigger Task
- Task Action: %AppDataLocal%\{GUID}\{Malware Filename}.exe --Task
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Ransomware Routine
This Ransomware renames encrypted files using the following names:
- {Original Filename}.{Original Extension}.zoqw
It drops the following file(s) as ransom note:
- {Encrypted Directory}\_readme.txt
SOLUTION
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.XXPE50FFF064
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
Step 5
Deleting Scheduled Tasks while in Safe Mode
- Still in safe mode, the following {Task Name}-{Task to be run} listed should be used in the steps identified below:
- Task Name: Time Trigger Task
- Task to be run: %AppDataLocal%\{GUID}\{Malware Filename}.exe --Task
- For Windows 7 and Server 2008 (R2) users, click Start>Computer.
- For Windows 8, 8.1, 10, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
- %System%\Tasks\{Task Name}
- Once located, select the file then press SHIFT+DELETE to delete it.
- Open Registry Editor. To do this:
- For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field, and press Enter.
- For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower left corner of the screen, click Run, type regedit in the text box
- In the left panel of the Registry Editor window, double-click the following:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
- Locate the created entry and take note of the registry value's data:
- ID={Task Data}
- After taking note of the data, delete the registry key:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
- In the left panel of the Registry Editor window, double-click the following:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tasks
- Still in the left panel, locate and delete the registry key with the same name as the located Task Data in step #6:
- ={Task Data}
- Close Registry Editor.
Step 6
Delete this registry value
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\Run
- SysHelper = %AppDataLocal%\{GUID}\{MalwareFilename}.exe --AutoStart
- SysHelper = %AppDataLocal%\{GUID}\{MalwareFilename}.exe --AutoStart
Step 7
Search and delete these files
- %System Root%\SystemID\PersonalID.txt
- %ProgramData%\{Random Numbers}
- %AppDataLocal%\bowsakkdestx.txt
- %Temporary Internet Files%\Content.IE5\YEFGVF95\build2.exe
- %Temporary Internet Files%\Content.IE5\YEFGVF95\116_203_9_69.txt
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.STOP.GE. 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.
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