Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a64f774b996ea2c…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:42:19 Authoring application: Microsoft Excel First seen: 2021-10-23
MD5: ffc881191b9d0891dc45709b5f2b2a4d SHA-1: e51e1f566aad276a19412d85ad8c9b50a0c2b069 SHA-256: 3a64f774b996ea2c2e9ae641174756ccf892ea8b74860d04d23d916a5b76ed46
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros. Heuristics indicate the presence of an Auto_Open defined name, which is a common technique for automatically executing malicious code upon opening the workbook. The XLM macros likely contain functionality to download and execute a secondary payload, although the specific URLs or commands are not directly visible in 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) 6910 bytes
SHA-256: 55c29f16cce891a43ca338879bb80e2ee4163f908095339cd02ebfb4eb79b451
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 -  nAlFEBkeA
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C154 
' 0018     27 LABEL : Cell Value, String Constant - AXdrCLJOxtQZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - CSqNNVgVSa len=0 
' 0018     27 LABEL : Cell Value, String Constant - CwcYlZkrpvwO len=0 
' 0018     23 LABEL : Cell Value, String Constant - cZWXkBkV len=0 
' 0018     24 LABEL : Cell Value, String Constant - eJHqyRGfp len=0 
' 0018     23 LABEL : Cell Value, String Constant - hcvttsUU len=0 
' 0018     25 LABEL : Cell Value, String Constant - HmQYxKqlOk len=0 
' 0018     24 LABEL : Cell Value, String Constant - MPkZGNvzg len=0 
' 0018     22 LABEL : Cell Value, String Constant - OaRktJq len=0 
' 0018     22 LABEL : Cell Value, String Constant - oUZybXx len=0 
' 0018     24 LABEL : Cell Value, String Constant - ozKBLSYZK len=0 
' 0018     23 LABEL : Cell Value, String Constant - PISaDFQJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - QTpOa len=0 
' 0018     21 LABEL : Cell Value, String Constant - rdwPQm len=0 
' 0018     27 LABEL : Cell Value, String Constant - rXleSqFjuCgw len=0 
' 0018     20 LABEL : Cell Value, String Constant - wPHSQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - xidITNGyCPL len=0 
' 0018     25 LABEL : Cell Value, String Constant - XIGWGlVFpi len=0 
' 0018     20 LABEL : Cell Value, String Constant - yJtHH len=0 
' 0018     22 LABEL : Cell Value, String Constant - YpKcYZZ 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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