Ransom.Win64.BUGO.A

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 executes then deletes itself afterward.

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

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:

• %User Temp%\temp.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

• %System%\cmd.exe /c start %User Temp%\temp.exe
• %System%\cmd.exe /c ping 127.0.0.1 & del %User Temp%\temp.exe
• %System%\cmd.exe /c start %Desktop%\Read_Bug.html

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It executes then deletes itself afterward.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• .7z
• .cs
• .db
• .gz
• .js
• .py
• .aac
• .asp
• .avi
• .bak
• .bat
• .bmp
• .cmd
• .com
• .cpp
• .css
• .csv
• .dbf
• .doc
• .exe
• .gif
• .htm
• .ico
• .jpg
• .jsp
• .lua
• .m3u
• .m4a
• .mdb
• .mid
• .mkv
• .mov
• .mp3
• .mp4
• .mpa
• .mpg
• .odt
• .ogg
• .pdb
• .pdf
• .php
• .png
• .ppt
• .psd
• .rar
• .rtf
• .sql
• .tif
• .txt
• .wav
• .xls
• .xml
• .zip
• .aspx
• .docx
• .html
• .java
• .jpeg
• .json
• .pptx
• .xlsx

It encrypts files found in the following folders:

• Drives A to Z
• %Desktop%
• %User Profile%\My Documents

(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It avoids encrypting files found in the following folders:

• Windows
• Program Files
• Users
• Program Files (x86)
• ProgramData
• Recovery
• PerfLogs
• Folder Name that contains any of the following special characters: $&()*+
• Folder Name that contains the string: System

It appends the following extension to the file name of the encrypted files:

• .bugbugo@{BLOCKED}mail.com].bug

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

• %Desktop%\Read_Bug.html
• %User Profile%\My Documents\Read_bug.html
• {Encrypted Folder}\Read_bug.html