Trojan.Win32.MSISTAH.A
HEUR:Trojan-Downloader.Win32.Agent.gen (Kaspersky)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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.
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.
Installation
This Trojan drops the following copies of itself into the affected system:
- %Application Data%\Macromedia\Flash Player\#SharedObjects\MRINFO.EXE
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- %System%\cmd.exe /c "COPY /Y /B "%User Temp%\fd9afa80b6e0ae7677b9be6e1fba3ad02d90fe33.scr" "%Application Data%\Macromedia\Flash Player\#SharedObjects\MRINFO.EXE""
- %System%\cmd.exe /c "COPY /Y /B "%User Temp%\5ed499d3.lnk" "%User Startup%\MRINFO.lnk""
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)
It creates the following folders:
- %Application Data%\season
- %Application Data%\tel\headline
- %Application Data%\season\INDEXTYPE\emailAddress
- %Application Data%\season\INDEXTYPE
- %User Profile%\AppData
- %Application Data%\season\INDEXTYPE\emailAddress\directory
- %Application Data%\Tag
- %Start Menu%\Programs\goutinessmonoamine
- %System Root%\Users
- %Application Data%\tel
- %Application Data%\tel\headline\hostid
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
Autostart Technique
This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\MRINFO.lnk
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)
Other System Modifications
This Trojan deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run\WIRE1x (2.5.1)
Dropping Routine
This Trojan drops the following files:
- %Application Data%\org.gnome.Terminal.Nautilus.metainfo.xml
- %Application Data%\Tag\lcrecundo.png
- %Application Data%\season\INDEXTYPE\emailAddress\directory\48.opends60.dll
- %Application Data%\season\INDEXTYPE\emailAddress\directory\GridView0804fig01.gif
- %Application Data%\Tag\odcunlock03.gif
- %Application Data%\app.jsl
- %Application Data%\season\INDEXTYPE\emailAddress\directory\IEExecRemote.dll
- %User Temp%\aspnetwp.exe
- %Application Data%\matrixkeypad.ko
- %Application Data%\9.opends60.dll
- %User Temp%\scsql9FileList.HxF
- %Application Data%\tel\headline\hostid\x-psf.xml
- %Application Data%\season\INDEXTYPE\emailAddress\directory\save-resume.page
- %Application Data%\season\INDEXTYPE\emailAddress\directory\media-optical-cd-audio-symbolic.svg
- %Application Data%\season\INDEXTYPE\emailAddress\directory\intfhelper.h
- %Application Data%\streamreader.cs
- %Application Data%\chinese.svg
- %Application Data%\season\INDEXTYPE\emailAddress\directory\ccissdefs.h
- %Application Data%\season\INDEXTYPE\emailAddress\directory\xlate.h
- %Application Data%\tel\headline\hostid\ultrachrome.xml
- %Application Data%\tel\headline\hostid\customizeToolbar.css
- %Application Data%\season\INDEXTYPE\emailAddress\directory\x-fluid.xml
- %Application Data%\regsvcs.exe
- %User Temp%\5ed499d3.lnk
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Identify and terminate files detected as Trojan.Win32.MSISTAH.A
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
Search and delete these components
- %Application Data%\org.gnome.Terminal.Nautilus.metainfo.xml
- %Application Data%\Tag\lcrecundo.png
- %Application Data%\season\INDEXTYPE\emailAddress\directory\48.opends60.dll
- %Application Data%\season\INDEXTYPE\emailAddress\directory\GridView0804fig01.gif
- %Application Data%\Tag\odcunlock03.gif
- %Application Data%\app.jsl
- %Application Data%\season\INDEXTYPE\emailAddress\directory\IEExecRemote.dll
- %User Temp%\aspnetwp.exe
- %Application Data%\matrixkeypad.ko
- %Application Data%\9.opends60.dll
- %User Temp%\scsql9FileList.HxF
- %Application Data%\tel\headline\hostid\x-psf.xml
- %Application Data%\season\INDEXTYPE\emailAddress\directory\save-resume.page
- %Application Data%\season\INDEXTYPE\emailAddress\directory\media-optical-cd-audio-symbolic.svg
- %Application Data%\season\INDEXTYPE\emailAddress\directory\intfhelper.h
- %Application Data%\streamreader.cs
- %Application Data%\chinese.svg
- %Application Data%\season\INDEXTYPE\emailAddress\directory\ccissdefs.h
- %Application Data%\season\INDEXTYPE\emailAddress\directory\xlate.h
- %Application Data%\tel\headline\hostid\ultrachrome.xml
- %Application Data%\tel\headline\hostid\customizeToolbar.css
- %Application Data%\season\INDEXTYPE\emailAddress\directory\x-fluid.xml
- %Application Data%\regsvcs.exe
- %User Temp%\5ed499d3.lnk
Step 5
Search and delete these folders
- %Application Data%\season
- %Application Data%\tel\headline
- %Application Data%\season\INDEXTYPE\emailAddress
- %Application Data%\season\INDEXTYPE
- %User Profile%\AppData
- %Application Data%\season\INDEXTYPE\emailAddress\directory
- %Application Data%\Tag
- %Start Menu%\Programs\goutinessmonoamine
- %System Root%\Users
- %Application Data%\tel
- %Application Data%\tel\headline\hostid
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.MSISTAH.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.
Step 7
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
- WIRE1x (2.5.1)
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