Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a7323320281d3c64…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:12 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 8588d17fbd2a32c00f50aafdcbe55427 SHA-1: d687d74523fa1f37b005101a67388b0126faf2a0 SHA-256: a7323320281d3c64a3aca9161e7699f8ffc99f01972314d251a0c2e992c7187c
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 large amount of obfuscated data, suggesting it is designed to download and execute a secondary payload. No specific IOCs like URLs or file hashes were directly extracted from the macro itself.

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) 6756 bytes
SHA-256: 5fd9213a84a144bdc367b7c67902455978d3558d6b136058456efbadf6675aa7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  seEfM
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D167 
' 0018     23 LABEL : Cell Value, String Constant - BFLqXVZw len=0 
' 0018     24 LABEL : Cell Value, String Constant - BqFWSuRJw len=0 
' 0018     25 LABEL : Cell Value, String Constant - CXkNJrRUFa len=0 
' 0018     25 LABEL : Cell Value, String Constant - DSHeVruKkU len=0 
' 0018     20 LABEL : Cell Value, String Constant - eYiKW len=0 
' 0018     26 LABEL : Cell Value, String Constant - GDVsighzudU len=0 
' 0018     24 LABEL : Cell Value, String Constant - kgxElMObr len=0 
' 0018     25 LABEL : Cell Value, String Constant - lIHysMezUS len=0 
' 0018     20 LABEL : Cell Value, String Constant - LPCNb len=0 
' 0018     27 LABEL : Cell Value, String Constant - LQXuCKWwBzpy len=0 
' 0018     20 LABEL : Cell Value, String Constant - nLVlX len=0 
' 0018     25 LABEL : Cell Value, String Constant - oeFKXCiLfa len=0 
' 0018     26 LABEL : Cell Value, String Constant - PtrRQefwHyq len=0 
' 0018     25 LABEL : Cell Value, String Constant - QyqmitmNfn len=0 
' 0018     20 LABEL : Cell Value, String Constant - RAVly len=0 
' 0018     25 LABEL : Cell Value, String Constant - RInwjGYzMa len=0 
' 0018     27 LABEL : Cell Value, String Constant - uEkbvqsfaJmK len=0 
' 0018     25 LABEL : Cell Value, String Constant - UtHVAyrZIn len=0 
' 0018     27 LABEL : Cell Value, String Constant - VynWlXtmvCEw len=0 
' 0018     20 LABEL : Cell Value, String Constant - weBoV 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
' 
... (truncated)

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