Ransom.Win32.SAMSAM.THGOHAI
Ransom:MSIL/Samas.A(Microsoft); MSIL/FilecoderSamas.A!tr.ransom(Fortinet)
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted:
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 encrypts files with specific file extensions. 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 and executes the following files:
- {malware path}\selfdel.exe
Other Details
This Ransomware does the following:
- Uses Bitcoin Address: {BLOCKED}DLTzkkT1uQrMPM42AUvfQN4Kds
- Uses C2 server: http://{BLOCKED}39k.wordpress.com
Ransomware Routine
This Ransomware encrypts files with the following extensions:
- xls
- xlsx
- doc
- docx
- ppt
- pptx
- txt
- dwg
- bak
- bkf
- pst
- dbx
- zip
- rar
- mdb
- asp
- aspx
- html
- htm
- dbf
- 3dm
- 3ds
- 3fr
- jar
- 3g2
- xml
- png
- tif
- 3gp
- java
- jpe
- jpeg
- jpg
- jsp
- php
- 3pr
- 7z
- ab4
- accdb
- accde
- accdr
- accdt
- ach
- kbx
- acr
- act
- adb
- ads
- agdl
- ai
- ait
- al
- apj
- arw
- asf
- asm
- asx
- avi
- awg
- back
- backup
- backupdb
- pbl
- bank
- bay
- bdb
- bgt
- bik
- bkp
- blend
- bpw
- c
- cdf
- cdr
- cdr3
- cdr4
- cdr5
- cdr6
- cdrw
- cdx
- ce1
- ce2
- cer
- cfp
- cgm
- cib
- class
- cls
- cmt
- cpi
- cpp
- cr2
- craw
- crt
- crw
- phtml
- php5
- cs
- csh
- csl
- tib
- csv
- dac
- db
- db3
- db-journal
- dc2
- dcr
- dcs
- ddd
- ddoc
- ddrw
- dds
- der
- des
- design
- dgc
- djvu
- dng
- dot
- docm
- dotm
- dotx
- drf
- drw
- dtd
- dxb
- dxf
- dxg
- eml
- eps
- erbsql
- erf
- exf
- fdb
- ffd
- fff
- fh
- fmb
- fhd
- fla
- flac
- flv
- fpx
- fxg
- gray
- grey
- gry
- h
- hbk
- hpp
- ibank
- ibd
- ibz
- idx
- iif
- iiq
- incpas
- indd
- kc2
- kdbx
- kdc
- key
- kpdx
- lua
- m
- m4v
- max
- mdc
- mdf
- mef
- mfw
- mmw
- moneywell
- mos
- mov
- mp3
- mp4
- mpg
- mrw
- msg
- myd
- nd
- ndd
- nef
- nk2
- nop
- nrw
- ns2
- ns3
- ns4
- nsd
- nsf
- nsg
- nsh
- nwb
- nx2
- nxl
- nyf
- oab
- obj
- odb
- odc
- odf
- odg
- odm
- odp
- ods
- odt
- oil
- orf
- ost
- otg
- oth
- otp
- ots
- ott
- p12
- p7b
- p7c
- pab
- pages
- pas
- pat
- pcd
- pct
- pdb
- pdd
- pef
- pem
- pfx
- pl
- plc
- pot
- potm
- potx
- ppam
- pps
- ppsm
- ppsx
- pptm
- prf
- ps
- psafe3
- psd
- pspimage
- ptx
- py
- qba
- qbb
- qbm
- qbr
- qbw
- qbx
- qby
- r3d
- raf
- rat
- raw
- rdb
- rm
- rtf
- rw2
- rwl
- rwz
- s3db
- sas7bdat
- say
- sd0
- sda
- sdf
- sldm
- sldx
- sql
- sqlite
- sqlite3
- sqlitedb
- sr2
- srf
- srt
- srw
- st4
- st5
- st6
- st7
- st8
- std
- sti
- stw
- stx
- svg
- swf
- sxc
- sxd
- sxg
- sxi
- sxi
- sxm
- sxw
- tex
- tga
- thm
- tlg
- vob
- war
- wallet
- wav
- wb2
- wmv
- wpd
- wps
- x11
- x3f
- xis
- xla
- xlam
- xlk
- xlm
- xlr
- xlsb
- xlsm
- xlt
- xltm
- xltx
- xlw
- ycbcra
- yuv
It avoids encrypting files with the following strings in their file path:
- Windows
- Reference Assemblies\Microsoft
- Recycle.Bin
It appends the following extension to the file name of the encrypted files:
- .encryptedRSA
It drops the following file(s) as ransom note:
- {encrypted directory}\HELP_DECRYPT_YOUR_FILES.HTML
SOLUTION
Step 1
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 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
Restart in Safe Mode
Step 4
Search and delete this file
- {malware path}\selfdel.exe
- {encrypted directories}\HELP_DECRYPT_YOUR_FILES.html
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.SAMSAM.THGOHAI. 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 6
Restore encrypted files from backup.
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