Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b5ff0341e6200207…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:44:32 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: 378c3dc47c8ec88ac570b9dce7f59da3 SHA-1: 8c403bb5791663d9f9b6a14158ca2583e2729898 SHA-256: b5ff0341e6200207b60e592686b67417db184adbf449650d04ffffe0d8cd0fec
140 Risk Score

Malware Insights

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

The file contains critical heuristic firings indicating the presence of Excel 4.0 macros with an Auto_Open defined name and dangerous formula APIs, specifically the RUN function. This suggests the macro is designed to execute arbitrary code upon opening the document. While no specific URLs or hashes were extracted, the presence of Auto_Open strongly implies a downloader or initial execution stage for further malicious activity.

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) 6834 bytes
SHA-256: 8bca15adfa977a7c0a3694191c019d134255fe41dcf865a3c54b2b3ebe4ee09f
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  LIOhsbAOf
' 0018     23 LABEL : Cell Value, String Constant - aPTyzcFM len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I150 
' 0018     24 LABEL : Cell Value, String Constant - BlAcAHJwO len=0 
' 0018     21 LABEL : Cell Value, String Constant - bngOym len=0 
' 0018     25 LABEL : Cell Value, String Constant - CkqTkPwSCO len=0 
' 0018     21 LABEL : Cell Value, String Constant - CKseOD len=0 
' 0018     27 LABEL : Cell Value, String Constant - eIXyNoWbSibe len=0 
' 0018     23 LABEL : Cell Value, String Constant - eUQHlkRm len=0 
' 0018     24 LABEL : Cell Value, String Constant - fGUXJEoVK len=0 
' 0018     24 LABEL : Cell Value, String Constant - GAkpoRqYm len=0 
' 0018     22 LABEL : Cell Value, String Constant - GJdAmey len=0 
' 0018     23 LABEL : Cell Value, String Constant - hjSyqkUc len=0 
' 0018     23 LABEL : Cell Value, String Constant - ICGNKSZN len=0 
' 0018     26 LABEL : Cell Value, String Constant - iVnPksLrtwE len=0 
' 0018     27 LABEL : Cell Value, String Constant - JZybZItybxpI len=0 
' 0018     23 LABEL : Cell Value, String Constant - LfueTxHm len=0 
' 0018     21 LABEL : Cell Value, String Constant - Nrfanm len=0 
' 0018     21 LABEL : Cell Value, String Constant - qaZTcA len=0 
' 0018     21 LABEL : Cell Value, String Constant - uwxUhY len=0 
' 0018     22 LABEL : Cell Value, String Constant - wtnyLhQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - YZYDqvNWLX 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)