Ransom.Win32.PHOBOS.B
N/A
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 file(s)/component(s):
- %System%\k.txt
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops and executes the following files:
- %User Temp%\{Random Number}.tmp\{Random Number}.tmp\{Random Number].bat
- %System%\{BLOCKED}.{BLOCKED}2000@aol.com.exe
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\{Random Characters}
Other System Modifications
This Ransomware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Enable = 1
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Size = 10
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
InitHits = 100
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Factor = 20
Other Details
This Ransomware adds the following lines or registry entries as part of its routine:
- HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
It does the following:
- Encrypts all logical drives found in the system
- It avoids the following directories:
- %Windows%
- %Program Files%
- It avoids encrypting files with the following file extensions:
- .doc
- .docx
- .ppt
- .pptx
- .xls
- .xlsx
- .jpg
- .jpeg
- .mdf
- .myd
- .tiff
- .tif
- .mdb
- .db
- .1cd
- .dbf
- .accdb
- .myi
- .frm
- .ldf
- .ndf
- .phobos
- It avoids to encrypt the following files:
- boot.ini
- bootfont.bin
- ntldr
- ntdetect.com
- io.sys
- Data.hta
- {BLOCKED}.{BLOCKED}2000@aol.com.exe
Ransomware Routine
This Ransomware appends the following extension to the file name of the encrypted files:
- {File Name}.{File Extension}.{ID-Volume Serial Number}.[{BLOCKED}.{BLOCKED}2000@aol.com].phobos
It drops the following file(s) as ransom note:
- %User Startup%\Data.hta
- %Common Startup%\Data.hta
- {Encrypted Logical Drive}\Data.hta
- {Encrypted Logical Drive}\Encrypted.txt
Shows the following as ransom note:
SOLUTION
Step 1
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 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
Restart in Safe Mode
Step 4
Delete this registry key
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.
- HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
Step 5
Search and delete these files
- %User Temp%\1544.tmp\1545.tmp\1546.bat
- %System%\ice.cream2000@aol.com.exe
- %System%\k.txt
- {Encrypted Logical Drive}\Encrypted.txt
- {Encrypted Logical Drive}\Data.hta
- %User Startup%\Data.hta
- %Common Startup%\Data.hta
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.PHOBOS.B. 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 7
Restore encrypted files from backup.
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