Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bf463f9ce1859de6…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:40:30 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: 6d16f0f57cdb3abafe86c2e6d184a639 SHA-1: f9184824f7f730fad34f1afad995bafbed6549fa SHA-256: bf463f9ce1859de61cf8de76a239820d591b81fe2d211e2a5e63a394e855b4e9
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a known method for executing malicious code. The macro sheet contains a reference to a dangerous formula API, suggesting it is designed to run arbitrary commands. The macro's purpose is likely to download and execute a second-stage payload, but no specific URLs or commands were extracted from the provided evidence.

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) 6737 bytes
SHA-256: 38aaee6f3073d958651ec118d17a10c0d200207f3720d63c8d03c8c1f888a3b1
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 -  qOFeweHzksc
' 0018     21 LABEL : Cell Value, String Constant - AeCyVu len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A149 
' 0018     21 LABEL : Cell Value, String Constant - fxQQpL len=0 
' 0018     21 LABEL : Cell Value, String Constant - fzmTnp len=0 
' 0018     25 LABEL : Cell Value, String Constant - gPRGJrAzCV len=0 
' 0018     22 LABEL : Cell Value, String Constant - jIEJWjD len=0 
' 0018     20 LABEL : Cell Value, String Constant - jXKlG len=0 
' 0018     24 LABEL : Cell Value, String Constant - LbkKrOjkW len=0 
' 0018     26 LABEL : Cell Value, String Constant - LbXDUKkswrY len=0 
' 0018     20 LABEL : Cell Value, String Constant - LLGqf len=0 
' 0018     22 LABEL : Cell Value, String Constant - lyiMNhY len=0 
' 0018     25 LABEL : Cell Value, String Constant - mBAvWgylAy len=0 
' 0018     26 LABEL : Cell Value, String Constant - mRLiviVsuKO len=0 
' 0018     25 LABEL : Cell Value, String Constant - MzEYmwungp len=0 
' 0018     27 LABEL : Cell Value, String Constant - nkAeSfsQPSqG len=0 
' 0018     27 LABEL : Cell Value, String Constant - OZBsLnNAjStg len=0 
' 0018     26 LABEL : Cell Value, String Constant - PWvUSPORvCx len=0 
' 0018     26 LABEL : Cell Value, String Constant - uPBOJtqpMWe len=0 
' 0018     26 LABEL : Cell Value, String Constant - VwFGQjdjgpH len=0 
' 0018     25 LABEL : Cell Value, String Constant - WhbCWhYoqM len=0 
' 0018     25 LABEL : Cell Value, String Constant - yPvvukLaIG 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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