RANSOM_GUSLOCKER.THAOAIAH
(Microsoft) Ransom:Win32/Sugolock, (ESET-NOD32) Win32/Filecoder.NSU
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
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
430080 bytes
EXE
No
Displays message/message boxes, 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 adds the following mutexes to ensure that only one of its copies runs at any one time:
- qweqwrqafsdgsdfg
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
inf = %User Profile%\DECRYPT.html
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
inf = %User Profile%\DECRYPT.html
Other Details
This Ransomware does the following:
- Displays the following when executed:
Ransomware Routine
This Ransomware encrypts files with the following extensions:
- .gdb
- .ldf
- .mdf
- .mdb
- .fdb
- .de
- .txt
- .png
- .jpg
- .jpeg
- .bmp
- .gif
- .zip
- .rar
- .7z
- .1cd
- .sql
- .bak
- .back
- .cab
- .log
- .ico
- .old
- .rtf
- .lnk
- .doc
- .docx
- .xls
- .xlsx
- .tif
- .vsc
- .mkv
- .flac
- .der
- .sch
- .crt
- .pem
- .pblix
- .hbk
- .epx
- .dpl
- .bpl
- .htm
- .csv
- .mp4
- .mp3
- .myi
- .myd
- .xml
- .r11
- .vsl
- .newdb
- .srf
- .pst
- .ods
- .dt
- .cf
- .erf
- .html
- .php
- .asp
- .aspx
- .js
- .ppt
- .pptx
- .java
- .cpp
- .css
- .h
- .c
- .jar
- .swift
- .os
- .shtml
- .less
- .sass
- .dat
- .json
- .key
- .avi
- .3gp
- .wmv
- .py
- .accdb
- .rmvb
- .mpg
- .mov
- .vob
- .flv
- .swf
- .wma
- .aac
- .mmf
- .amr
- .m4a
- .m4r
- .ogg
- .mp2
- .wav
- .tif
- .pcx
- .tga
- .tiff
- .odt
- .dll
- .exe
- .rf
- .glf
- .msi
- .vhdx
- .vhd
- .bin
- .vsv
- .tib
- .vue
- .mrimg
It encrypts files found in the following folders:
- {All Drives}\
- C:\1a\
It avoids encrypting files with the following strings in their file name:
- DECRYPT.html
- {Malware Filename}.exe
It avoids encrypting files with the following strings in their file path:
- Windows
- Windows.old
- ProgramFiles
- ProgramFiles (x86)
- All Users
- Intel
- $Recycle.Bin
- Recycle.Bin
- $RECYCLE.BIN
- ProgramData
It appends the following extension to the file name of the encrypted files:
- .GUSv2
It drops the following file(s) as ransom note:
- {Encrypted Directory}\DECRYPT.html
SOLUTION
9.850
14.594.04
29 Oct 2018
14.595.00
30 Oct 2018
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_GUSLOCKER.THAOAIAH
- 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.
- 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.
- 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
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\Run
- inf = "%User Profile%\DECRYPT.html"
- inf = "%User Profile%\DECRYPT.html"
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- inf = "%User Profile%\DECRYPT.html"
- inf = "%User Profile%\DECRYPT.html"
Step 5
Search and delete these files
- {Encrypted Directory}\DECRYPT.html
Step 6
Scan your computer with your Trend Micro product to delete files detected as RANSOM_GUSLOCKER.THAOAIAH. 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 the following Trend Micro Support pages for more information:
Step 7
Restore encrypted files from backup.
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