Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 79724369bc5a0112…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:42:43 Authoring application: Microsoft Excel First seen: 2021-07-02
MD5: c54f0fbf44add6b1ceb950567a2b2014 SHA-1: 7a5852554c83d48c929aa24c7e06daedbe565a32 SHA-256: 79724369bc5a011298b397f98b37726c020a7d25f80873e86b5e21b79c8d8720
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This is a common technique for downloading and executing further malicious payloads.

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) 6550 bytes
SHA-256: 720cdb7ec9de7b57ef6fe8abeae4b2c9ad65cee46e944e355b586b545d547259
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  gkmKcTJF
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A183 
' 0018     26 LABEL : Cell Value, String Constant - BZWUASoOnvD len=0 
' 0018     26 LABEL : Cell Value, String Constant - djGlJNMAMgs len=0 
' 0018     21 LABEL : Cell Value, String Constant - DnLhHJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - dvPeJe len=0 
' 0018     27 LABEL : Cell Value, String Constant - gavvEBDMkPQQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - HvIIy len=0 
' 0018     24 LABEL : Cell Value, String Constant - IlBeipVrd len=0 
' 0018     24 LABEL : Cell Value, String Constant - mJcuyjvFX len=0 
' 0018     27 LABEL : Cell Value, String Constant - MRASQnCytaUs len=0 
' 0018     27 LABEL : Cell Value, String Constant - PxQboAplgAOe len=0 
' 0018     26 LABEL : Cell Value, String Constant - RBLUqDVPCZy len=0 
' 0018     22 LABEL : Cell Value, String Constant - rLZZZqq len=0 
' 0018     22 LABEL : Cell Value, String Constant - SIQobwr len=0 
' 0018     27 LABEL : Cell Value, String Constant - skeutgNIPAOr len=0 
' 0018     20 LABEL : Cell Value, String Constant - sQKPM len=0 
' 0018     22 LABEL : Cell Value, String Constant - TdupeVv len=0 
' 0018     20 LABEL : Cell Value, String Constant - xCjMO len=0 
' 0018     26 LABEL : Cell Value, String Constant - XGRnqsByxHC len=0 
' 0018     24 LABEL : Cell Value, String Constant - yMQFfrFEn len=0 
' 0018     22 LABEL : Cell Value, String Constant - zCBmgGj 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
' 00
... (truncated)

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