Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1d0f9c70a8148e3a…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:29:07 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: acffd78cb217af92f734472b9257fdb6 SHA-1: 7d4826bed7435c918c20ed5f3e3a7421528468d9 SHA-256: 1d0f9c70a8148e3acfe5d7ed72dd9bcb74bf4fdf6900f70de5fe207b48fb9413
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary code upon opening, which is a common technique for delivering secondary payloads. The presence of dangerous formula APIs in the Auto_Open macro further indicates malicious intent.

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) 6557 bytes
SHA-256: 2991f8dd8ff37c5709ea23a9db508511535d506f2d8dc16383d4c10146938a4d
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 -  rFUqjqBIy
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C174 
' 0018     26 LABEL : Cell Value, String Constant - bwimdvtRgos len=0 
' 0018     24 LABEL : Cell Value, String Constant - cugZPrUaa len=0 
' 0018     22 LABEL : Cell Value, String Constant - daynwcF len=0 
' 0018     26 LABEL : Cell Value, String Constant - DMhXaOWtDHe len=0 
' 0018     26 LABEL : Cell Value, String Constant - erYKCZoTtyv len=0 
' 0018     24 LABEL : Cell Value, String Constant - fbCRkEYdw len=0 
' 0018     20 LABEL : Cell Value, String Constant - gkxzT len=0 
' 0018     21 LABEL : Cell Value, String Constant - LmEuMZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - LnMDFZvb len=0 
' 0018     25 LABEL : Cell Value, String Constant - mhpUsmdmCM len=0 
' 0018     24 LABEL : Cell Value, String Constant - ohvgFQCGq len=0 
' 0018     21 LABEL : Cell Value, String Constant - riAOHh len=0 
' 0018     20 LABEL : Cell Value, String Constant - smRRU len=0 
' 0018     23 LABEL : Cell Value, String Constant - USVgGdtj len=0 
' 0018     20 LABEL : Cell Value, String Constant - uxFbB len=0 
' 0018     26 LABEL : Cell Value, String Constant - vjKQDkpIvFc len=0 
' 0018     27 LABEL : Cell Value, String Constant - VwxJhqhrnLFP len=0 
' 0018     21 LABEL : Cell Value, String Constant - xiPhAm len=0 
' 0018     22 LABEL : Cell Value, String Constant - YScbJTB len=0 
' 0018     22 LABEL : Cell Value, String Constant - zaOKRxM 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     10 
... (truncated)

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