Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 06ac78d26db55a2a…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:29 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 6c7ba66104e2ab7dbb718bdc07331344 SHA-1: 4046a7dd77198c7a22df718cfc4520489cec57da SHA-256: 06ac78d26db55a2aa9e8c2c675e8bf5735ddf11b6b5d5612e9a9d115acad2c06
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 sheet containing an Auto_Open function, indicated by critical heuristic firings. This suggests the macro is designed to execute automatically upon opening the workbook. The presence of dangerous formula APIs in the Auto_Open function further points to malicious intent, 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) 6676 bytes
SHA-256: 4d9f7469ab1b571baf872da54b6b3f00f6b37ce1d54c7b5c888afd82086425ad
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  doYvp
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F186 
' 0018     24 LABEL : Cell Value, String Constant - GevhdJssC len=0 
' 0018     23 LABEL : Cell Value, String Constant - GEyEzOFd len=0 
' 0018     23 LABEL : Cell Value, String Constant - HfotKcet len=0 
' 0018     23 LABEL : Cell Value, String Constant - hiirKiXr len=0 
' 0018     24 LABEL : Cell Value, String Constant - idxHkqFSh len=0 
' 0018     20 LABEL : Cell Value, String Constant - IFkqY len=0 
' 0018     20 LABEL : Cell Value, String Constant - iJlST len=0 
' 0018     22 LABEL : Cell Value, String Constant - KZdqTOV len=0 
' 0018     27 LABEL : Cell Value, String Constant - LenVVrgEYIKn len=0 
' 0018     26 LABEL : Cell Value, String Constant - NOOujQHCNAK len=0 
' 0018     23 LABEL : Cell Value, String Constant - PVNmdAyU len=0 
' 0018     24 LABEL : Cell Value, String Constant - QmGVCHjaw len=0 
' 0018     20 LABEL : Cell Value, String Constant - rsIwN len=0 
' 0018     20 LABEL : Cell Value, String Constant - SUhfs len=0 
' 0018     22 LABEL : Cell Value, String Constant - TgQaKMs len=0 
' 0018     22 LABEL : Cell Value, String Constant - tvXEYly len=0 
' 0018     20 LABEL : Cell Value, String Constant - vKbZH len=0 
' 0018     25 LABEL : Cell Value, String Constant - wkDENpSEOd len=0 
' 0018     27 LABEL : Cell Value, String Constant - zlBbjolkYRfa len=0 
' 0018     26 LABEL : Cell Value, String Constant - zmyuieIFvKI 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 LABELS
... (truncated)

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