Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 81a367b68f1114c2…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:35 Authoring application: Microsoft Excel First seen: 2021-09-29
MD5: 0b4f356fc2fe38a102d3813159a4a521 SHA-1: 58e32a60cf178a8e9112f38d9012197de5140757 SHA-256: 81a367b68f1114c283f752dcf1e3e177b097662742448ca2a3e42a9289034dd9
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open function. This function is designed to execute automatically when the workbook is opened, indicating a malicious intent to run arbitrary code. The presence of dangerous formula APIs like 'RUN' further supports this assessment.

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) 6419 bytes
SHA-256: ba1658e979118b45ce488108c58233ac09fb4a1e6cdb0df142014e28c05157de
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  jicH
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G147 
' 0018     23 LABEL : Cell Value, String Constant - BJRHnBgr len=0 
' 0018     23 LABEL : Cell Value, String Constant - FsrWyTCi len=0 
' 0018     22 LABEL : Cell Value, String Constant - fxBRYJG len=0 
' 0018     25 LABEL : Cell Value, String Constant - GNmCarvOMN len=0 
' 0018     27 LABEL : Cell Value, String Constant - HWfBObQCnOog len=0 
' 0018     27 LABEL : Cell Value, String Constant - irEZiKRCPtLC len=0 
' 0018     23 LABEL : Cell Value, String Constant - JhNrhmGr len=0 
' 0018     27 LABEL : Cell Value, String Constant - JkalHAWwvLXr len=0 
' 0018     27 LABEL : Cell Value, String Constant - JztnksJpTqkT len=0 
' 0018     27 LABEL : Cell Value, String Constant - lbizONQjWNNJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - LLpDLgCSDfJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - qDpZyUrT len=0 
' 0018     23 LABEL : Cell Value, String Constant - QIOdzMWs len=0 
' 0018     20 LABEL : Cell Value, String Constant - rpeDr len=0 
' 0018     21 LABEL : Cell Value, String Constant - VnPYcp len=0 
' 0018     27 LABEL : Cell Value, String Constant - WCTGJVgEhQBw len=0 
' 0018     20 LABEL : Cell Value, String Constant - WiAjR len=0 
' 0018     23 LABEL : Cell Value, String Constant - WmEPpKGr len=0 
' 0018     23 LABEL : Cell Value, String Constant - XhJWgqYc len=0 
' 0018     21 LABEL : Cell Value, String Constant - YfBZgu 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
' 00
... (truncated)

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