Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3d5364db03ba0c00…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:18 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: aa659120a58cb2129a433b6212715f2e SHA-1: f64d9bc2260026129ab35fcc45abaae0f3063b1c SHA-256: 3d5364db03ba0c0021b7f75e508b9f9e8a649e04297dde116897eb02c109b2e9
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. The macro sheet contains a dangerous formula API call, suggesting it's designed to run arbitrary commands. The presence of an Auto_Open entry strongly implies the macro will execute automatically upon opening the document, likely to download and execute a secondary 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) 6872 bytes
SHA-256: b3fc69181abbb10133045399225e3bc05f2aeb7f53cc0b0bc58526178ab338c8
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  RwyhINJzsFW
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H141 
' 0018     22 LABEL : Cell Value, String Constant - dCNQvJG len=0 
' 0018     23 LABEL : Cell Value, String Constant - fwISNPVo len=0 
' 0018     23 LABEL : Cell Value, String Constant - gyzDKRlr len=0 
' 0018     26 LABEL : Cell Value, String Constant - iFvGyohtedQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - ivXgqgSoD len=0 
' 0018     20 LABEL : Cell Value, String Constant - Kebpm len=0 
' 0018     22 LABEL : Cell Value, String Constant - NKQvYbu len=0 
' 0018     26 LABEL : Cell Value, String Constant - nmQRgMryLyU len=0 
' 0018     20 LABEL : Cell Value, String Constant - OMhqC len=0 
' 0018     23 LABEL : Cell Value, String Constant - onbaLTwF len=0 
' 0018     26 LABEL : Cell Value, String Constant - pEkMCADBlwO len=0 
' 0018     21 LABEL : Cell Value, String Constant - pwywix len=0 
' 0018     24 LABEL : Cell Value, String Constant - sLCPFtVqf len=0 
' 0018     21 LABEL : Cell Value, String Constant - TsrDfz len=0 
' 0018     27 LABEL : Cell Value, String Constant - UFyfAXcEFgDG len=0 
' 0018     23 LABEL : Cell Value, String Constant - umElFyHk len=0 
' 0018     26 LABEL : Cell Value, String Constant - VJWixtLNfeM len=0 
' 0018     27 LABEL : Cell Value, String Constant - vzSVOCMwYXBv len=0 
' 0018     25 LABEL : Cell Value, String Constant - wUWpTmkqeI len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZthWE 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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