Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d2dcc281c33f9d98…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:41:24 Authoring application: Microsoft Excel First seen: 2021-11-03
MD5: f117d312d10e9b343672967037b1724b SHA-1: 6db37b7313c21e733c4a1b0e9e6f7ecc8f7c9643 SHA-256: d2dcc281c33f9d98011a4f705f8309cf127e1918cb062d65b74dca21ed58e00e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an Excel file containing Excel 4.0 (XLM) macros, specifically an Auto_Open defined name. This indicates an attempt to automatically execute code when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro is intended to download and execute a second-stage payload, a common technique for initial compromise.

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) 6901 bytes
SHA-256: b4d6b6bb2e3e2c57388434ea856debe4a9767babc87a7dec64d58ca2bd82fac2
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 -  CsYVeKLcv
' 0018     20 LABEL : Cell Value, String Constant - acJCb len=0 
' 0018     25 LABEL : Cell Value, String Constant - aDYsdKJGBE len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D171 
' 0018     25 LABEL : Cell Value, String Constant - bKQrGNgJqH len=0 
' 0018     25 LABEL : Cell Value, String Constant - cDQizmPORl len=0 
' 0018     23 LABEL : Cell Value, String Constant - DpOWUXaJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - DyqQUM len=0 
' 0018     22 LABEL : Cell Value, String Constant - EDNTKbF len=0 
' 0018     24 LABEL : Cell Value, String Constant - FTDaYlbES len=0 
' 0018     27 LABEL : Cell Value, String Constant - irBGoITtixHw len=0 
' 0018     24 LABEL : Cell Value, String Constant - kNEaaNNqK len=0 
' 0018     24 LABEL : Cell Value, String Constant - makYfcTdw len=0 
' 0018     23 LABEL : Cell Value, String Constant - MAWLpSjL len=0 
' 0018     22 LABEL : Cell Value, String Constant - mHvbsPW len=0 
' 0018     27 LABEL : Cell Value, String Constant - NiHsqvGtksKM len=0 
' 0018     25 LABEL : Cell Value, String Constant - RcVjXSabSG len=0 
' 0018     23 LABEL : Cell Value, String Constant - RtgyIYUJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - SngwG len=0 
' 0018     25 LABEL : Cell Value, String Constant - UoNbFbunme len=0 
' 0018     20 LABEL : Cell Value, String Constant - VGxuV len=0 
' 0018     22 LABEL : Cell Value, String Constant - vqVtayw 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    
... (truncated)

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