Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 847a3fe277669573…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:42:46 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: 49a4326a8045e844868e04182c6fed2b SHA-1: 1d88055a653b0971198d2f13a363ac18a671f259 SHA-256: 847a3fe2776695739bcb56e4b214810fbea2edbd7bfcebc63a5ade7578372cc2
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open defined name. This indicates an attempt to automatically execute code upon opening the document. The presence of dangerous formula APIs like RUN suggests the macro is designed 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) 6565 bytes
SHA-256: df1102d053df5804c1d541e9dbcfbed0e59194b3de3c6dcbd13e0855dd8bb7b0
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  QyLYIJxoOd
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E191 
' 0018     22 LABEL : Cell Value, String Constant - cKPoLwo len=0 
' 0018     22 LABEL : Cell Value, String Constant - EkfgUda len=0 
' 0018     24 LABEL : Cell Value, String Constant - FhiXYuFWQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - GHbZyyUio len=0 
' 0018     21 LABEL : Cell Value, String Constant - HqNRCL len=0 
' 0018     26 LABEL : Cell Value, String Constant - hwmwOqmZEfP len=0 
' 0018     23 LABEL : Cell Value, String Constant - jWHDOKBx len=0 
' 0018     21 LABEL : Cell Value, String Constant - mlBXII len=0 
' 0018     23 LABEL : Cell Value, String Constant - OKDIiTWq len=0 
' 0018     22 LABEL : Cell Value, String Constant - pXCsRYA len=0 
' 0018     24 LABEL : Cell Value, String Constant - RIazZmVBT len=0 
' 0018     20 LABEL : Cell Value, String Constant - RXlGs len=0 
' 0018     27 LABEL : Cell Value, String Constant - sHPyLDLmGRlx len=0 
' 0018     23 LABEL : Cell Value, String Constant - taEEjbju len=0 
' 0018     21 LABEL : Cell Value, String Constant - UHLpKx len=0 
' 0018     21 LABEL : Cell Value, String Constant - uVtcPp len=0 
' 0018     23 LABEL : Cell Value, String Constant - WaGYZeTq len=0 
' 0018     23 LABEL : Cell Value, String Constant - WzPemNms len=0 
' 0018     24 LABEL : Cell Value, String Constant - XkPLPbHct len=0 
' 0018     23 LABEL : Cell Value, String Constant - YjBlcMnV 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     10 LABEL
... (truncated)

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