Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c670e5d2c57f7885…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:45:16 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 0ab2f7fb01f6ee24d5bf8c71ba81256c SHA-1: 65dfd08214370a41f5936e1727bed04e00851bf7 SHA-256: c670e5d2c57f788528f73068e769057b8e8b13f59168c367c241c167204d4c48
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open macro. This indicates an attempt to execute arbitrary code upon opening the document. The presence of dangerous formula APIs in the Auto_Open macro suggests the execution of malicious functions, 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) 6889 bytes
SHA-256: 006e6cbe2cc33591ddcac738f3972fd3d2e3257671db6e35105b6ccaf5c4fcf9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  yOJBjQXgjh
' 0018     24 LABEL : Cell Value, String Constant - aKCychrgY len=0 
' 0018     24 LABEL : Cell Value, String Constant - ASLayRzdO len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A169 
' 0018     23 LABEL : Cell Value, String Constant - bswYkApz len=0 
' 0018     20 LABEL : Cell Value, String Constant - cccTV len=0 
' 0018     20 LABEL : Cell Value, String Constant - EUpRU len=0 
' 0018     26 LABEL : Cell Value, String Constant - fukPWwJvrkY len=0 
' 0018     25 LABEL : Cell Value, String Constant - gxfzlJZfFQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - iuWhSVWpo len=0 
' 0018     24 LABEL : Cell Value, String Constant - mclGDiVYr len=0 
' 0018     22 LABEL : Cell Value, String Constant - mzzwBxO len=0 
' 0018     25 LABEL : Cell Value, String Constant - PWHEiMKiOy len=0 
' 0018     24 LABEL : Cell Value, String Constant - pZGDuCVeJ len=0 
' 0018     27 LABEL : Cell Value, String Constant - sNNNcCVItGQY len=0 
' 0018     25 LABEL : Cell Value, String Constant - UHgocVPCCo len=0 
' 0018     25 LABEL : Cell Value, String Constant - uQkqTkSXjo len=0 
' 0018     23 LABEL : Cell Value, String Constant - vdIlMJGK len=0 
' 0018     23 LABEL : Cell Value, String Constant - vGdtWwYp len=0 
' 0018     20 LABEL : Cell Value, String Constant - xnKBD len=0 
' 0018     25 LABEL : Cell Value, String Constant - XoYpEFyjzU len=0 
' 0018     24 LABEL : Cell Value, String Constant - zxxChsAbj 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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