RANSOM_CRYPTESLA.USVNC15
Ransomware-FGN!C0DBBF36B0B6 (McAfee)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It connects to certain websites to send and receive information. It deletes the initially executed copy of itself. It gathers information and reports it to its servers.
TECHNICAL DETAILS
403,892 bytes
EXE
Yes
15 Mar 2016
Connects to URLs/IPs, Encrypts files
Arrival Details
This Trojan 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 Trojan drops the following copies of itself into the affected system and executes them:
- %Windows%\{random filename}.exe (with Administrator Privileges)
- %My Documents%\{random}.exe (with non-Administrator Privileges)
(Note: %My Documents% is usually C:\Documents and Settings\{user name}\My Documents on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Documents on Windows Vista and 7.)
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It drops the following files:
- Ransom notes:
- {folders containing encrypted files}\RECOVER{random 5 characters}.txt
- {folders containing encrypted files}\RECOVER{random 5 characters}.png
- {folders containing encrypted files}\RECOVER{random 5 characters}.html
- %Desktop%\RECOVER{random 5 characters}.txt
- %Desktop%\RECOVER{random 5 characters}.png
- %Desktop%\RECOVER{random 5 characters}.html
- %My Documents%\RECOVER{random 5 characters}.txt
- %My Documents%\RECOVER{random 5 characters}.png
- %My Documents%\RECOVER{random 5 characters}.html
- %My Documents%\recover.txt
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
_{random characters} = "%System%\cmd.exe /c start %Windows%\{random filename}.exe" (with Administrator Privileges)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
_{random characters} = "%System%\cmd.exe /c start %My Documents%\{random filename}.exe" (with non-Administrator Privileges)
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\trueimg
HKEY_CURRENT_USER\Software\{ID}
It adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLinkedConnections = "1"
To enable Windows to share network connections
HKEY_CURRENT_USER\Software\trueimg
ID = "{ID}"
Other Details
This Trojan connects to the following website to send and receive information:
- http://{BLOCKED}15.com/strbin.php
- http://{BLOCKED}garden.com/strbin.php
- http://{BLOCKED}k.com/binstr.php
- http://{BLOCKED}ument.co.uk/strbin.php
- http://{BLOCKED}athart.com/binstr.php
- http://{BLOCKED}wyerdesign.com/wp-content/plugins/binstr.php
- http://{BLOCKED}15.com/strbin.php
- http://{BLOCKED}garden.com/strbin.php
- http://{BLOCKED}k.com/binstr.php
It encrypts files with the following extensions:
- .lvl
- .arch00
- .ntl
- .fsh
- .itdb
- .itl
- .mddata
- .sidd
- .sidn
- .bkf
- .qic
- .bkp
- .bc7
- .bc6
- .pkpass
- .tax
- .gdb
- .qdf
- .t12
- .t13
- .ibank
- .sum
- .sie
- .zip
- .w3x
- .rim
- .psk
- .tor
- .vpk
- .iwd
- .mlx
- .fpk
- .dazip
- .vtf
- .vcf
- .esm
- .blob
- .dmp
- .layout
- .menu
- .kf
- .ncf
- .sid
- .sis
- .ztmp
- .vdf
- .mov
- .fos
- .itm
- .wmo
- .itm
- .map
- .wmo
- .svg
- .cas
- .gho
- .syncdb
- .hkdb
- .hplg
- .hvpl
- .icxs
- .docm
- .wps
- .xls
- .xlsx
- .xlsm
- .xlsb
- .xlk
- .ppt
- .pptx
- .pptm
- .mdb
- .accdb
- .pst
- .dwg
- .dxg
- .wpd
- .rtf
- .wb2
- .pfx
- .p12
- .p7b
- .sb
- .mdbackup
- .xf
- .p7c
- .txt
- .jpeg
- .png
- .css
- .flv
- .m3u
- .desc
- .xxx
- wallet
- .big
- .pak
- .rgss3a
- .epk
- .bik
- .slm
- .lbf
- .sav
- .re4
- .apk
- .bsa
- .ltx
- .forge
- .asset
- .iwi
- .das
- .upk
- .d3dbsp
- .csv
- .wmv
- .avi
- .wma
- .m4a
- .rar
- .mp4
- .sql
- .bak
- .tiff
- .com
- .py
- .js
- .rb
- .litesql
- .litemod
- .7z
- .x3f
- .der
- .cer
- .crt
- .pem
- .odt
- .ods
- .odp
- .odm
- .odc
- .odb
- .doc
- .docx
It deletes the initially executed copy of itself
It gathers the following information and reports it to its servers:
- IP address
- OS version
- installation id (inst_id)
- ID value from the registry HKEY_CURRENT_USER\Software\trueimg
NOTES:
This malware does not append an extension to the encrypted files.
It encrypts files in all fixed, removable, and network drives and shares.
It executes the following command to delete shadow copies:
vssadmin.exe Delete Shadows /All /Quiet
It opens the following ransom notes after encryption:
SOLUTION
9.800
12.404.07
15 Mar 2016
12.405.00
16 Mar 2016
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
Scan your computer with your Trend Micro product and note files detected as RANSOM_CRYPTESLA.USVNC15
Step 4
Restart in Safe Mode
Step 5
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
- _{random characters} = "%System%\cmd.exe /c start %Windows%\{random filename}.exe"
- _{random characters} = "%System%\cmd.exe /c start %Windows%\{random filename}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- _{random characters} = "%System%\cmd.exe /c start %My Documents%\{random filename}.exe"
- _{random characters} = "%System%\cmd.exe /c start %My Documents%\{random filename}.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLinkedConnections = "1"
- EnableLinkedConnections = "1"
Step 6
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.
- In HKEY_CURRENT_USER\Software
- trueimg
- trueimg
- In HKEY_CURRENT_USER\Software
- {ID}
- {ID}
Step 7
Search and delete this file
- %My Documents%\recover.txt
- RECOVER{random 5 characters}.txt
- RECOVER{random 5 characters}.png
- RECOVER{random 5 characters}.html
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CRYPTESLA.USVNC15. 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.
Did this description help? Tell us how we did.