Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 10a12419de74d3e6…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:46 Authoring application: Microsoft Excel First seen: 2021-10-02
MD5: a49f66946fb3c3e35e2feaa9edc3a240 SHA-1: c1226f6f6cd655b6c2256a8fb79a492858dd83e1 SHA-256: 10a12419de74d3e63e818ecab0579a27523fbbefc7bb24d029b0c90e7cb69f65
140 Risk Score

Malware Insights

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

This Excel file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code. The presence of dangerous formula APIs in the Auto_Open macro indicates an intent to run arbitrary commands. The macro sheet itself contains obfuscated strings and potentially malicious formulas, suggesting it's designed 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) 6755 bytes
SHA-256: a52a7f714a25a6c74f0cca6f6f5ebc41c67edf8a03def4cf94931e752b08ad0b
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 -  TRWiWXuw
' 0018     27 LABEL : Cell Value, String Constant - AfJJmaXQteIc len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B179 
' 0018     22 LABEL : Cell Value, String Constant - AvFpqmG len=0 
' 0018     24 LABEL : Cell Value, String Constant - CthvExVMa len=0 
' 0018     26 LABEL : Cell Value, String Constant - dilQZBagLrR len=0 
' 0018     26 LABEL : Cell Value, String Constant - EhJMAocyWbB len=0 
' 0018     24 LABEL : Cell Value, String Constant - EHrjrzEMf len=0 
' 0018     20 LABEL : Cell Value, String Constant - JXnEf len=0 
' 0018     22 LABEL : Cell Value, String Constant - laHbUBO len=0 
' 0018     26 LABEL : Cell Value, String Constant - MKcPJKxspCA len=0 
' 0018     23 LABEL : Cell Value, String Constant - OtGacqiw len=0 
' 0018     20 LABEL : Cell Value, String Constant - qVwQD len=0 
' 0018     22 LABEL : Cell Value, String Constant - QxkFfpV len=0 
' 0018     20 LABEL : Cell Value, String Constant - spzHU len=0 
' 0018     27 LABEL : Cell Value, String Constant - tsrkzIxgRCHd len=0 
' 0018     26 LABEL : Cell Value, String Constant - VByJyympMNy len=0 
' 0018     22 LABEL : Cell Value, String Constant - WAUNHCJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - wknrK len=0 
' 0018     25 LABEL : Cell Value, String Constant - WvyvZKBVLr len=0 
' 0018     25 LABEL : Cell Value, String Constant - xWNrwmYFVc len=0 
' 0018     21 LABEL : Cell Value, String Constant - zeuGUm 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    
... (truncated)

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