Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b1ece0efa1516d37…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:22 Authoring application: Microsoft Excel First seen: 2021-09-27
MD5: c11bef887f6870775d523f3ebf05cab4 SHA-1: ae3d1e954fd48f45564e1501ee598dbd39e21c99 SHA-256: b1ece0efa1516d3750fe241de9902fa15a8ed0dd0c7231ff1cde9cf23905e190
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 common technique for executing malicious code. The macro sheet contains a reference to 'Auto_Open', suggesting it will run automatically when the workbook is opened. The presence of dangerous formula APIs further increases the risk. No specific IOCs like URLs or hashes were extracted, but the technique itself is highly suspicious.

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) 6861 bytes
SHA-256: fc01d4235ba187c9d6b2af84c695d5a9f7621591def7e261f602497005c902f5
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 -  DjTKqJpyL
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G166 
' 0018     27 LABEL : Cell Value, String Constant - EGKbbBBZFwWo len=0 
' 0018     27 LABEL : Cell Value, String Constant - EuKDrTWvEQge len=0 
' 0018     26 LABEL : Cell Value, String Constant - gWSmNkgMLMN len=0 
' 0018     26 LABEL : Cell Value, String Constant - ICtVEwzCzSR len=0 
' 0018     21 LABEL : Cell Value, String Constant - iVtKwJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - kiGkApeolFr len=0 
' 0018     27 LABEL : Cell Value, String Constant - MdyAcLKDsEzD len=0 
' 0018     27 LABEL : Cell Value, String Constant - myXDNViBFzou len=0 
' 0018     21 LABEL : Cell Value, String Constant - NRGquu len=0 
' 0018     23 LABEL : Cell Value, String Constant - nSEoDHce len=0 
' 0018     21 LABEL : Cell Value, String Constant - pbcFdH len=0 
' 0018     23 LABEL : Cell Value, String Constant - qNJqzQcR len=0 
' 0018     24 LABEL : Cell Value, String Constant - RuYjYrvJJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - StNwcvNzeuz len=0 
' 0018     22 LABEL : Cell Value, String Constant - wLiyvFi len=0 
' 0018     27 LABEL : Cell Value, String Constant - WnkaiPCMdWNA len=0 
' 0018     27 LABEL : Cell Value, String Constant - wWjbqAWicCHv len=0 
' 0018     22 LABEL : Cell Value, String Constant - XlLbXSU len=0 
' 0018     27 LABEL : Cell Value, String Constant - zitNdbjHEqGW len=0 
' 0018     23 LABEL : Cell Value, String Constant - zQyuQfRZ 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, Strin
... (truncated)

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