Technical Information
To ensure autorun and distribution
Modifies the following registry keys
- [<HKCU>\Software\Microsoft\Windows\CurrentVersion\Run] 'Windows_Antimalware_Host_Syst' = '%ALLUSERSPROFILE%\MicrosoftCorporation\Windows\System32\Isass.exe'
Creates or modifies the following files
- <SYSTEM32>\tasks\windows_antimalware_host_systm
- <SYSTEM32>\tasks\windows_antimalware_host
- %APPDATA%\microsoft\windows\start menu\programs\startup\isass.lnk
Malicious functions
Executes the following
- '%WINDIR%\syswow64\taskkill.exe' /im <File name>.exe /f
Injects code into
the following user processes:
- isass.exe
Modifies file system
Creates the following files
- %ALLUSERSPROFILE%\microsoftcorporation\windows\system32\isass.exe
- %ALLUSERSPROFILE%\windowsappcertification\windowhelperstoragehostsystemthread.ps1
- %ALLUSERSPROFILE%\windowsappcertification\checker.vbs
- %ALLUSERSPROFILE%\windowsappcertification\cert.cmd
- <Current directory>\createshortcut.vbs
Deletes the following files
- <Current directory>\createshortcut.vbs
Deletes itself.
Network activity
Connects to
- 'ap#.#oomed.cf':80
TCP
HTTP POST requests
- http://ap#.#oomed.cf/2.0/method/checkConnection
UDP
- DNS ASK ap#.#oomed.cf
Miscellaneous
Searches for the following windows
- ClassName: '' WindowName: ''
Creates and executes the following
- '%ALLUSERSPROFILE%\microsoftcorporation\windows\system32\isass.exe'
- '%ALLUSERSPROFILE%\microsoftcorporation\windows\system32\isass.exe' ' (with hidden window)
- '%WINDIR%\syswow64\cmd.exe' /c taskkill /im <File name>.exe /f & erase <Full path to file> & exit' (with hidden window)
- '%WINDIR%\syswow64\schtasks.exe' /Create /SC MINUTE /MO 30 /TN "Windows_Antimalware_Host" /TR "%ALLUSERSPROFILE%\WindowsAppCertification\checker.vbs" /F' (with hidden window)
- '%WINDIR%\syswow64\schtasks.exe' /Create /SC MINUTE /MO 5 /TN "Windows_Antimalware_Host_Systm" /TR "%ALLUSERSPROFILE%\MicrosoftCorporation\Windows\System32\Isass.exe" /F' (with hidden window)
- '%WINDIR%\syswow64\cmd.exe' /c echo Set oWS = WScript.CreateObject("WScript.Shell") > CreateShortcut.vbs & echo sLinkFile = "%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\Isass.lnk" >> Create...' (with hidden window)
Executes the following
- '%WINDIR%\syswow64\cmd.exe' /c taskkill /im <File name>.exe /f & erase <Full path to file> & exit
- '%WINDIR%\syswow64\schtasks.exe' /Create /SC MINUTE /MO 30 /TN "Windows_Antimalware_Host" /TR "%ALLUSERSPROFILE%\WindowsAppCertification\checker.vbs" /F
- '%WINDIR%\syswow64\schtasks.exe' /Create /SC MINUTE /MO 5 /TN "Windows_Antimalware_Host_Systm" /TR "%ALLUSERSPROFILE%\MicrosoftCorporation\Windows\System32\Isass.exe" /F
- '%WINDIR%\syswow64\cmd.exe' /c echo Set oWS = WScript.CreateObject("WScript.Shell") > CreateShortcut.vbs & echo sLinkFile = "%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\Isass.lnk" >> Create...
- '%WINDIR%\syswow64\cscript.exe' CreateShortcut.vbs
