Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0b4f5bf171551f55…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:46:08 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 3e1c507543824acd8d8373dd94784546 SHA-1: 6beda402fb20474de27980c118086a1bd6ec2389 SHA-256: 0b4f5bf171551f5519af5128502edaf1d2d4c6764c2da99a3170e285117896e2
140 Risk Score

Malware Insights

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

The sample contains Excel 4.0 macros, specifically an Auto_Open macro, which is a critical finding. This indicates the file is designed to automatically execute code upon opening. The presence of dangerous formula APIs like RUN 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) 6611 bytes
SHA-256: 959108a1381bff5ca088dc32c60d34f7bfcedc7357bf8b68c2284d1265deefc2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  JyFGbjc
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H178 
' 0018     26 LABEL : Cell Value, String Constant - bnuRopDNcYV len=0 
' 0018     25 LABEL : Cell Value, String Constant - BOeFXqpxfS len=0 
' 0018     24 LABEL : Cell Value, String Constant - dQwrJGyhn len=0 
' 0018     20 LABEL : Cell Value, String Constant - EpiYx len=0 
' 0018     26 LABEL : Cell Value, String Constant - etlOHqffFEI len=0 
' 0018     27 LABEL : Cell Value, String Constant - joOgIvzCuTFF len=0 
' 0018     25 LABEL : Cell Value, String Constant - lJsLMxpWWQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - mYJiIzXZl len=0 
' 0018     23 LABEL : Cell Value, String Constant - OsUzUIHK len=0 
' 0018     20 LABEL : Cell Value, String Constant - oVOKs len=0 
' 0018     23 LABEL : Cell Value, String Constant - pcWKmrnv len=0 
' 0018     25 LABEL : Cell Value, String Constant - taCJEnoEre len=0 
' 0018     24 LABEL : Cell Value, String Constant - TJXGoHdew len=0 
' 0018     22 LABEL : Cell Value, String Constant - TrmwsOb len=0 
' 0018     26 LABEL : Cell Value, String Constant - txHioBUZOLR len=0 
' 0018     22 LABEL : Cell Value, String Constant - UQoCKxj len=0 
' 0018     27 LABEL : Cell Value, String Constant - wrlZzleCyiOa len=0 
' 0018     25 LABEL : Cell Value, String Constant - YgBvhcyXsj len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZFFgkVOka len=0 
' 0018     23 LABEL : Cell Value, String Constant - zwGydGWC 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/ SS
... (truncated)

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