Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f6fb9c833ebcd0ae…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:47:08 Authoring application: Microsoft Excel First seen: 2021-10-16
MD5: c83ab6a0170a8f06dff0f2fe85f6ac1a SHA-1: cb87dc9f53eb9a22859c3daf927168018b0b2644 SHA-256: f6fb9c833ebcd0ae8ffb2073eb94efe3e15861fcbfd277bbe0f4cdbc3ce38080
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 document detected with critical heuristics for Auto_Open functionality and the use of dangerous formula APIs like RUN. This indicates the macro is designed to execute arbitrary code upon opening, a common technique for downloading and executing further malicious payloads. No specific family could be identified from the available evidence.

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) 6410 bytes
SHA-256: 8ae72a0c2839486001d64b190bc8eaa88f8fb94b305662e7f902156e71a815d6
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  DrYl
' 0018     22 LABEL : Cell Value, String Constant - aLfNXNw len=0 
' 0018     25 LABEL : Cell Value, String Constant - AoOxTSdaaa len=0 
' 0018     25 LABEL : Cell Value, String Constant - aPogICSvFM len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A185 
' 0018     20 LABEL : Cell Value, String Constant - bsglz len=0 
' 0018     25 LABEL : Cell Value, String Constant - diqtUjMhru len=0 
' 0018     20 LABEL : Cell Value, String Constant - fgztQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - GEhwjliH len=0 
' 0018     25 LABEL : Cell Value, String Constant - ITRCIJOHqr len=0 
' 0018     21 LABEL : Cell Value, String Constant - kQVtmD len=0 
' 0018     21 LABEL : Cell Value, String Constant - LabKGE len=0 
' 0018     27 LABEL : Cell Value, String Constant - LgnpAEAibdxi len=0 
' 0018     21 LABEL : Cell Value, String Constant - LIGBWo len=0 
' 0018     20 LABEL : Cell Value, String Constant - MzlJV len=0 
' 0018     20 LABEL : Cell Value, String Constant - qcDEy len=0 
' 0018     20 LABEL : Cell Value, String Constant - Qmmfo len=0 
' 0018     24 LABEL : Cell Value, String Constant - rNyXnDXAa len=0 
' 0018     27 LABEL : Cell Value, String Constant - StGNmMQgisGm len=0 
' 0018     23 LABEL : Cell Value, String Constant - WaQrPIeN len=0 
' 0018     27 LABEL : Cell Value, String Constant - ydExFmvwdAGx len=0 
' 0018     25 LABEL : Cell Value, String Constant - YwZKjapSmJ 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 LABELSS
... (truncated)

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