Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bd75351383b7b516…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:47:31 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: fb695328f5afa8aad041bebf014f067d SHA-1: 85e40ac25016d9c36c5951cd35dce767e8536da7 SHA-256: bd75351383b7b516d592b2e0e83f88a529c38071e4d25c8807554b73e51493b6
140 Risk Score

Malware Insights

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

The file contains critical heuristic firings indicating the presence of Excel 4.0 (XLM) macros with an Auto_Open entry and dangerous formula APIs, specifically the RUN function. This suggests the macro is designed to execute arbitrary code upon opening the document. While no specific URLs or payloads were extracted, the presence of these dangerous XLM functions strongly implies the intent to download and execute a second-stage payload.

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) 6873 bytes
SHA-256: 4a2cc46df549f83416ca4d449a83f93e791c53df4e2234a3da0fafcfe222e193
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  IkpTWhVef
' 0018     24 LABEL : Cell Value, String Constant - aAKjcLKDQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - aMXYDUQjnNq len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A162 
' 0018     20 LABEL : Cell Value, String Constant - BgjkN len=0 
' 0018     20 LABEL : Cell Value, String Constant - cPtea len=0 
' 0018     27 LABEL : Cell Value, String Constant - GYKFyMcyvbin len=0 
' 0018     25 LABEL : Cell Value, String Constant - hCQNrSMYLf len=0 
' 0018     27 LABEL : Cell Value, String Constant - iJSdMlISAixx len=0 
' 0018     26 LABEL : Cell Value, String Constant - ijSsTHprqkk len=0 
' 0018     24 LABEL : Cell Value, String Constant - MwWmsOZCn len=0 
' 0018     23 LABEL : Cell Value, String Constant - oDGjyPAG len=0 
' 0018     27 LABEL : Cell Value, String Constant - OhIhyeFHhclG len=0 
' 0018     23 LABEL : Cell Value, String Constant - PZCUnSlZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - QxJypEgGU len=0 
' 0018     24 LABEL : Cell Value, String Constant - rCwEEQIrZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - RDfYqEm len=0 
' 0018     27 LABEL : Cell Value, String Constant - sJMSHwtIwrbS len=0 
' 0018     22 LABEL : Cell Value, String Constant - uhfzWIs len=0 
' 0018     22 LABEL : Cell Value, String Constant - ULNJDUT len=0 
' 0018     26 LABEL : Cell Value, String Constant - wohunJMSeeY len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZpYKeDj 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/ 
... (truncated)

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