LNK_KOVTER.SM
Exploit.Poweliks.Gen.3 (BITDEFENDER)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 may be downloaded by other malware/grayware/spyware from remote sites.
TECHNICAL DETAILS
1,033 bytes
LNK
Yes
11 Jul 2017
Drops 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.
It may be downloaded by other malware/grayware/spyware from remote sites.
Installation
This Trojan drops the following files:
- %Application Data%\{random string}\{random}.lnk - link to Batch file
- %Application Data%\{random string}\{random}.bat - starts Encrypted file
- %Application Data%\{random string}\{random}.{random extension 1} - Encrypted file
- %Start Menu%\Programs\Startup\{random}.lnk
(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.. %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.)
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
(Default) = %Application Data%\{random string}\{random}.bat
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CLASSES_ROOT\.{random extension 1}
(Default) = "{random value 1}"
HKEY_CLASSES_ROOT\{random value 1}\shell\
open\command
(Default) = mshta \"about:(script){variable 1}=\"s5KE\";{variable 2}=new ActiveXObject(\"WScript.Shell\");{variable 3}=\"oepop\";{variable 4}={variable 2}.RegRead(\"HKCU\\software\\{random string 1}\\{name 2}\");{variable 5}=\"Ijwl\";eval({variable 4});{variable 6}=\"nb2Wjac\";(/script)\""
HKEY_CURRENT_USER\Software\{random string 1}
{multiple registry name} = "{multiple encrypted data}"
Other Details
This Trojan does the following:
- It executes the following command:
- start "random string" "%LOCALAPPDATA%\{random}\{random}.{random}"
SOLUTION
9.850
13.514.05
05 Jul 2017
13.515.00
06 Jul 2017
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 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_CLASSES_ROOT
- .{random extension 1}
- .{random extension 1}
- In HKEY_CURRENT_USER\Software
- {random string 1}
- {random string 1}
- In HKEY_CLASSES_ROOT
- {random value 1}
- {random value 1}
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
- (Default) = %Application Data%\{random string}\{random}.bat
- (Default) = %Application Data%\{random string}\{random}.bat
Step 6
Search and delete this folder
- %Application Data%\{random string}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as LNK_KOVTER.SM. 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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