Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f98f5edb847316ff…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:48 Authoring application: Microsoft Excel First seen: 2021-10-11
MD5: dc47c92c2a5213724f55a5c6a36abd6c SHA-1: 0f4bccf1e85f7524bd329cd620cbc8b1b50fae93 SHA-256: f98f5edb847316ff0183aa938019ee1af1ef7ceb80703af56576cc2fb2721d99
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 entry, which is a critical finding. The presence of dangerous formula APIs like RUN indicates the macro is designed to execute commands. This strongly suggests the macro is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6706 bytes
SHA-256: 976959136b4bed7a462a29ab6a585c11a3b7146361cd23e6bf7b95204ad33773
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 -  ozKuR
' 0018     27 LABEL : Cell Value, String Constant - AIbRFklxmgGP len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B181 
' 0018     20 LABEL : Cell Value, String Constant - BRpvp len=0 
' 0018     27 LABEL : Cell Value, String Constant - cGqvcyxlzPad len=0 
' 0018     24 LABEL : Cell Value, String Constant - CppyaNStc len=0 
' 0018     22 LABEL : Cell Value, String Constant - dJycphr len=0 
' 0018     26 LABEL : Cell Value, String Constant - DzAxaFpjOiT len=0 
' 0018     27 LABEL : Cell Value, String Constant - euaFceknYvYB len=0 
' 0018     22 LABEL : Cell Value, String Constant - HdZNXBl len=0 
' 0018     25 LABEL : Cell Value, String Constant - IGrWhDceHo len=0 
' 0018     25 LABEL : Cell Value, String Constant - jOHQBuHImV len=0 
' 0018     21 LABEL : Cell Value, String Constant - Jpegcg len=0 
' 0018     25 LABEL : Cell Value, String Constant - jxPvwrpwXK len=0 
' 0018     27 LABEL : Cell Value, String Constant - NNffTCHxXCAj len=0 
' 0018     26 LABEL : Cell Value, String Constant - ojvlkWayBEt len=0 
' 0018     24 LABEL : Cell Value, String Constant - ptOSZtqea len=0 
' 0018     23 LABEL : Cell Value, String Constant - qsMzyTIL len=0 
' 0018     25 LABEL : Cell Value, String Constant - SfyRbcqvTe len=0 
' 0018     27 LABEL : Cell Value, String Constant - UkirYEguvqMn len=0 
' 0018     22 LABEL : Cell Value, String Constant - XcTycGa len=0 
' 0018     25 LABEL : Cell Value, String Constant - YEASyZVsYR 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 Const
... (truncated)

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