RANSOM_CRYSIS.HTP
Trojan.Ransom.Crysis.E (BitDefender), a variant of Win32/Filecoder.Crysis.P (ESET-NOD32), Ransom:Win32/Wadhrama (Microsoft)
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 is capable of encrypting files in the affected system.
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 copies of itself into the affected system:
- %System%\{Malware Filename}.exe (if admin)
- %Application Data%\{Malware Filename}.exe (if non-admin)
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
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
{Malware Filename}.exe = %System%\{Malware Filename}.exe
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{Malware Filename}.exe = %Application Data%\{Malware Filename}.exe
It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %Start Menu%\Programs\Startup\{Malware Filename}.exe
- %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\{Malware Filename}.exe
(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%System%\Info.hta = mshta.exe "%System%\Info.hta"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%Application Data%\Info.hta = mshta.exe "%Application Data%\Info.hta"
Other Details
This Ransomware is capable of encrypting files in the affected system.
Ransomware Routine
This Ransomware appends the following extension to the file name of the encrypted files:
- .id-{ID}.[briannayl0fcbrown@{BLOCKED}l.com].bip
It drops the following file(s) as ransom note:
- {All Drives}\FILES ENCRYPTED.txt
- {Public User Desktop}\FILES ENCRYPTED.txt
- %Desktop%\FILES ENCRYPTED.txt
- %Start Menu%\Programs\Startup\Info.hta
- %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\Info.hta
- %System%\Info.hta
- %Application Data%\Info.hta
(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
SOLUTION
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
Restart in Safe Mode
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
- {Malware Filename}.exe = %System%\{Malware Filename}.exe
- {Malware Filename}.exe = %System%\{Malware Filename}.exe
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {Malware Filename}.exe = %Application Data%\{Malware Filename}.exe
- {Malware Filename}.exe = %Application Data%\{Malware Filename}.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- %System%\Info.hta = mshta.exe "%System%\Info.hta"
- %System%\Info.hta = mshta.exe "%System%\Info.hta"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- %Application Data%\Info.hta = mshta.exe "%Application Data%\Info.hta"
- %Application Data%\Info.hta = mshta.exe "%Application Data%\Info.hta"
Step 5
Search and delete these files
- %System%\{Malware Filename}.exe
- %Application Data%\{Malware Filename}.exe
- %Start Menu%\Programs\Startup\{Malware Filename}.exe
- %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\{Malware Filename}.exe
- {All Drives}\FILES ENCRYPTED.txt
- {Public User Desktop}\FILES ENCRYPTED.txt
- %Desktop%\FILES ENCRYPTED.txt
- %Start Menu%\Programs\Startup\Info.hta
- %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\Info.hta
- %System%\Info.hta
- %Application Data%\Info.hta
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CRYSIS.HTP. 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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