Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 38bb74eafb6797dd…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:56 Authoring application: Microsoft Excel First seen: 2021-05-23
MD5: f7f1e1b08c3220b8bc5f12356a669954 SHA-1: 8975e54140a53883c25cfeae2de69a948a7dbb71 SHA-256: 38bb74eafb6797ddadf38ef0ef5b296eff3971e76ee441d86d6dcdca761c76ee
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates that the workbook is configured to automatically execute macros upon opening. The presence of dangerous formula APIs like RUN further suggests that these macros are intended to perform malicious actions, likely by executing arbitrary code or downloading further payloads.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6657 bytes
SHA-256: 9c67bd328b44dc4a9d540bdced0143154cec3b1b85ab5be5b9390e5ff242174a
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  GnxRLuhCLsO
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F187 
' 0018     22 LABEL : Cell Value, String Constant - BkFSSaQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - dFKJEGdrFA len=0 
' 0018     25 LABEL : Cell Value, String Constant - eHzoIvDrqN len=0 
' 0018     26 LABEL : Cell Value, String Constant - gttaYXVadSz len=0 
' 0018     20 LABEL : Cell Value, String Constant - HNSIw len=0 
' 0018     24 LABEL : Cell Value, String Constant - iMizUGVYy len=0 
' 0018     27 LABEL : Cell Value, String Constant - jLMlKCMmFIEy len=0 
' 0018     24 LABEL : Cell Value, String Constant - jovobIxGk len=0 
' 0018     25 LABEL : Cell Value, String Constant - kPrQfzwtMB len=0 
' 0018     20 LABEL : Cell Value, String Constant - LPTKQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - mTtLaKON len=0 
' 0018     21 LABEL : Cell Value, String Constant - MvxtWm len=0 
' 0018     26 LABEL : Cell Value, String Constant - oMheDuotDyx len=0 
' 0018     22 LABEL : Cell Value, String Constant - pmnZkZx len=0 
' 0018     21 LABEL : Cell Value, String Constant - sybSfG len=0 
' 0018     25 LABEL : Cell Value, String Constant - TfwLespvBX len=0 
' 0018     22 LABEL : Cell Value, String Constant - WnvHbtd len=0 
' 0018     22 LABEL : Cell Value, String Constant - wXkxsPD len=0 
' 0018     27 LABEL : Cell Value, String Constant - xAiwsdRTReho len=0 
' 0018     27 LABEL : Cell Value, String Constant - XHpFFRGoVUGw len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
'
... (truncated)

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