RANSOM_KILLERLOCKER.A
Trojan-Ransom.MSIL.Kilo.a (Kaspersky); Ransom.KillerLocker (Malwarebytes);
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 employs registry shell spawning by adding certain registry entries. This allows this malware to execute even when other applications are opened.
TECHNICAL DETAILS
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.
Autostart Technique
This Trojan drops the following files:
- %Desktop%\key.txt [contains encryption key]
(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.)
It employs registry shell spawning to ensure its execution when certain file types are accessed by adding the following entries:
HKEY_CLASSES_ROOT\Rip\Shell\
edit\command
{default} = ""{Malwarefile file path and filename}",%1"
HKEY_CLASSES_ROOT\Rip\Shell\
open\command
{default} = ""{Malwarefile file path and filename}",%1"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CLASSES_ROOT\.rip
{Default} = "Rip"
HKEY_CLASSES_ROOT\Rip
{default} = "encrypt .rip"
HKEY_CLASSES_ROOT\Rip\DefaultIcon
{default} = ""{Malwarefile file path and filename}",0"
Other Details
This Trojan renames encrypted files using the following names:
- {original filename and file extension}.rip
It does the following:
- It encrypts on the following filepaths
- {DesktopDirectory special folder file path}
- %Desktop%
- %User Profile%\My Pictures
- %AppDataLocal%
- %Program Files%
- %System%
- %User Startup%
- %Start Menu%\Programs
- %User Profile%\My Documents
- %User Profile%\Templates
(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.)
NOTES:
This ransomware displays the following image after execution:
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_CLASSES_ROOT\.rip
- {default} = "Rip"
- {default} = "Rip"
- In HKEY_CLASSES_ROOT\Rip
- {default} = "encrypt .rip"
- {default} = "encrypt .rip"
- In HKEY_CLASSES_ROOT\Rip\DefaultIcon
- {default} = ""{Malwarefile file path and filename}",0"
- {default} = ""{Malwarefile file path and filename}",0"
Step 5
Restore this modified registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CLASSES_ROOT\Rip\Shell\edit\command
- {default} = ""{Malwarefile file path and filename}",%1"
- {default} = ""{Malwarefile file path and filename}",%1"
- In HKEY_CLASSES_ROOT\Rip\Shell\open\command
- {default} = ""{Malwarefile file path and filename}",%1"
- {default} = ""{Malwarefile file path and filename}",%1"
Step 6
Search and delete this file
- %Desktop%\key.txt
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_KILLERLOCKER.A. 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.
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