Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f4b09d83334c8cc9…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:29:14 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: 029159bef012deae30debda77b447322 SHA-1: 8b2942462fad0d3ba2ed0da15c52b8f4b480e4a7 SHA-256: f4b09d83334c8cc96428f02b523b0f577e0313c48803d79e630c92a0eafff35f
140 Risk Score

Malware Insights

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

The file is an Excel spreadsheet containing Excel 4.0 macros. A critical heuristic identified an Auto_Open defined name, indicating that macros will execute automatically upon opening the document. This is a common technique for initial execution of malicious payloads.

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) 6487 bytes
SHA-256: adeb5ed1e05afe38c34da0d1d1f1b80bbbb7d08eae20608c984478083f24a9e5
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  VMyJtn
' 0018     21 LABEL : Cell Value, String Constant - ApvvuL len=0 
' 0018     22 LABEL : Cell Value, String Constant - AQEcvNu len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A181 
' 0018     21 LABEL : Cell Value, String Constant - cLCvAd len=0 
' 0018     27 LABEL : Cell Value, String Constant - eHUKjNCALzty len=0 
' 0018     26 LABEL : Cell Value, String Constant - fbvsKSsHDat len=0 
' 0018     24 LABEL : Cell Value, String Constant - HPTkgQruQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - hRvCXmm len=0 
' 0018     23 LABEL : Cell Value, String Constant - IABXnpoM len=0 
' 0018     27 LABEL : Cell Value, String Constant - JLLhsCWSeqTM len=0 
' 0018     26 LABEL : Cell Value, String Constant - JUacwgiyfhz len=0 
' 0018     24 LABEL : Cell Value, String Constant - OqTHlwUwe len=0 
' 0018     24 LABEL : Cell Value, String Constant - qHTWNAyWP len=0 
' 0018     23 LABEL : Cell Value, String Constant - qLjesEEc len=0 
' 0018     26 LABEL : Cell Value, String Constant - TXdNZmadEud len=0 
' 0018     26 LABEL : Cell Value, String Constant - UuHiJlfXvLM len=0 
' 0018     24 LABEL : Cell Value, String Constant - XDWxjfpjv len=0 
' 0018     20 LABEL : Cell Value, String Constant - xvtHs len=0 
' 0018     23 LABEL : Cell Value, String Constant - zarSaShW len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZFvLcn len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZOrpMFxlpcAQ 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
' 0
... (truncated)

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