Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 477a1c342ed770f7…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:34:33 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 6c704f5f993cb73e6b96d38534bc837e SHA-1: 84197f17c128ca36ebbcd755968ce285b291f1b1 SHA-256: 477a1c342ed770f7f4afcee361d1eb03a1447b9a5a9ed1bf398a126a1abe6428
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. The presence of dangerous formula APIs like RUN indicates the macro is designed to execute commands or download additional payloads. This is a common method for initial execution in macro-enabled documents.

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) 6501 bytes
SHA-256: c93512163a50d26c730338f4f2b8b40b7475f6b8dd4b99fc0a7afb53dcf6ee8b
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  EsW
' 0018     24 LABEL : Cell Value, String Constant - AbgTaYsAq len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C160 
' 0018     23 LABEL : Cell Value, String Constant - BygpHwUW len=0 
' 0018     26 LABEL : Cell Value, String Constant - bzKnjHmGhdv len=0 
' 0018     27 LABEL : Cell Value, String Constant - CLCzPwYufkRS len=0 
' 0018     25 LABEL : Cell Value, String Constant - CqhgSTDmbq len=0 
' 0018     23 LABEL : Cell Value, String Constant - cSyqAdnv len=0 
' 0018     26 LABEL : Cell Value, String Constant - dmzYlLJPsXH len=0 
' 0018     27 LABEL : Cell Value, String Constant - EqaFxwIhERGd len=0 
' 0018     26 LABEL : Cell Value, String Constant - FXgbCaisEuR len=0 
' 0018     22 LABEL : Cell Value, String Constant - LnzIToH len=0 
' 0018     26 LABEL : Cell Value, String Constant - nwwNzkzsXQN len=0 
' 0018     25 LABEL : Cell Value, String Constant - ojVQVvedwY len=0 
' 0018     25 LABEL : Cell Value, String Constant - oMrbsbledl len=0 
' 0018     26 LABEL : Cell Value, String Constant - QgNOGUoDSOD len=0 
' 0018     24 LABEL : Cell Value, String Constant - RtmCSbUQG len=0 
' 0018     22 LABEL : Cell Value, String Constant - rZbGBrY len=0 
' 0018     23 LABEL : Cell Value, String Constant - VoBIQTCj len=0 
' 0018     20 LABEL : Cell Value, String Constant - wgMTS len=0 
' 0018     27 LABEL : Cell Value, String Constant - WIjhlLeYdLos len=0 
' 0018     27 LABEL : Cell Value, String Constant - XPkWAajxxKyf 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 Con
... (truncated)

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