Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6ddb737531d8b87f…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:32 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: 691b407ca07b0b785da00674f45f9c0a SHA-1: df8b3d574288b206fdb0f919e0697f73da90ba47 SHA-256: 6ddb737531d8b87ff2d142eda020755cbe5a9929bb3aa9bc856c639c111d74a7
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 defined name, which is a known technique for executing malicious code upon opening the document. The macro sheet contains a reference to 'Auto_Open', suggesting it's designed to run automatically. The presence of dangerous formula APIs further supports malicious intent, likely 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) 6540 bytes
SHA-256: f32935af4eadfb40f25c716d20206daf980eaf7f9decf8b6c569db57f3e1d1c7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  hSG
' 0018     27 LABEL : Cell Value, String Constant - APzQOYvuESgg len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A138 
' 0018     22 LABEL : Cell Value, String Constant - BfsvqQB len=0 
' 0018     20 LABEL : Cell Value, String Constant - biqdh len=0 
' 0018     22 LABEL : Cell Value, String Constant - cbTDXuz len=0 
' 0018     25 LABEL : Cell Value, String Constant - cuoaPiTeZd len=0 
' 0018     23 LABEL : Cell Value, String Constant - DfgdpnCc len=0 
' 0018     21 LABEL : Cell Value, String Constant - fpLHZM len=0 
' 0018     27 LABEL : Cell Value, String Constant - JvIUWRjItxvE len=0 
' 0018     20 LABEL : Cell Value, String Constant - kccbk len=0 
' 0018     27 LABEL : Cell Value, String Constant - kgZpOdMgTyXe len=0 
' 0018     26 LABEL : Cell Value, String Constant - luROWfSefUy len=0 
' 0018     21 LABEL : Cell Value, String Constant - mhDkif len=0 
' 0018     27 LABEL : Cell Value, String Constant - NCIOkpLzPDJy len=0 
' 0018     20 LABEL : Cell Value, String Constant - NDXIT len=0 
' 0018     22 LABEL : Cell Value, String Constant - pVAErdC len=0 
' 0018     24 LABEL : Cell Value, String Constant - QFQUxbkNu len=0 
' 0018     20 LABEL : Cell Value, String Constant - RPEbT len=0 
' 0018     24 LABEL : Cell Value, String Constant - SOxQTIPrX len=0 
' 0018     24 LABEL : Cell Value, String Constant - UbINKryKE len=0 
' 0018     21 LABEL : Cell Value, String Constant - YPHxau 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
' 00fd     10 LABELS
... (truncated)

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