TROJ_RANSOM.IHN
Trojan.Win32.Buzus.nubp(Kaspersky),W32/Rimecud.gen.aw(NAI)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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 executes then deletes itself afterward.
TECHNICAL DETAILS
313,856 bytes
EXE
No
16 Jul 2013
Modifies files, Displays graphics/image
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 files:
- %Application Data%\africa.bmp
- %Application Data%\Microsoft\Windows\Start Menu\Programs\Startup\africa.bmp
- %Application Data%\Microsoft\Windows\Start Menu\Programs\Startup\cleen.bat - deletes the initial malware and the deletes the batch file itself
(Note: %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.)
It executes then deletes itself afterward.
Autostart Technique
This Trojan drops the following file(s) in the Windows Common Startup folder to enable its automatic execution at every system startup:
- %Application Data%\Microsoft\Windows\Start Menu\Programs\Startup\{malware file name and extension} - Copy of itself
(Note: %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.)
Other System Modifications
This Trojan changes the desktop wallpaper by modifying the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Application Data%\africa.bmp"
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"
It sets the system's desktop wallpaper to the following image:
Other Details
This Trojan encrypts files with the following extensions:
- .jpg
- .jpeg
- .doc
- .rtf
- .xls
- .zip
- .db3
- .rar
- .7z
- .docx
- .odt
- .ppt
- .mdb
- .dwg
- .xml
- .dt
- .gsf
- .ppsx
- .pptx
- .xlsx
- .1cd
- .dbf
It renames encrypted files using the following names:
- {file name and extension}.sos@{BLOCKED}e.com_T3
NOTES:
This Trojan encrypts files using RSA encryption, which needs a private key from the cybercriminal in order to decrypt the encrypted files.
SOLUTION
9.300
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
Reset your Desktop properties
Step 3
Search and delete these files
- %Application Data%\africa.bmp
- %Application Data%\Microsoft\Windows\Start Menu\Programs\Startup\africa.bmp
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_RANSOM.IHN . 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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