Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8c691895e9089242…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:46:56 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: a297bba4c11215166b246db3fec92ff9 SHA-1: 5b8de9903fee88872e74646aceff5d881794e054 SHA-256: 8c691895e9089242447b13410fcf878435771acf03c96f8fae9cea3eb7d42862
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs, specifically 'RUN', suggests the macro is designed to execute external commands. While the exact payload is not visible, the technique strongly implies the download and execution of a second-stage malicious file.

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) 6433 bytes
SHA-256: 36d7c495099120d19259305198da7de9535dbae4bba7b424aeacfb08b95cffc6
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  WPV
' 0018     23 LABEL : Cell Value, String Constant - ArvKKGNa len=0 
' 0018     27 LABEL : Cell Value, String Constant - aSKjgFZqIsfA len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G181 
' 0018     27 LABEL : Cell Value, String Constant - bCVoZRSZTTfU len=0 
' 0018     27 LABEL : Cell Value, String Constant - BSTShmoKvtgb len=0 
' 0018     23 LABEL : Cell Value, String Constant - btYDeCne len=0 
' 0018     21 LABEL : Cell Value, String Constant - cKmQQR len=0 
' 0018     22 LABEL : Cell Value, String Constant - cuWUqAA len=0 
' 0018     20 LABEL : Cell Value, String Constant - fnaRw len=0 
' 0018     21 LABEL : Cell Value, String Constant - lizSpr len=0 
' 0018     25 LABEL : Cell Value, String Constant - mbKdxFzkPk len=0 
' 0018     25 LABEL : Cell Value, String Constant - MWbKoSClCc len=0 
' 0018     26 LABEL : Cell Value, String Constant - oGcbvUeyOoP len=0 
' 0018     20 LABEL : Cell Value, String Constant - OIAtd len=0 
' 0018     27 LABEL : Cell Value, String Constant - pdAoZpsrMWTR len=0 
' 0018     21 LABEL : Cell Value, String Constant - ShZXAD len=0 
' 0018     27 LABEL : Cell Value, String Constant - SShyDLfxRGkq len=0 
' 0018     20 LABEL : Cell Value, String Constant - sSZCm len=0 
' 0018     24 LABEL : Cell Value, String Constant - UoYwXWPxY len=0 
' 0018     20 LABEL : Cell Value, String Constant - zeQBl len=0 
' 0018     24 LABEL : Cell Value, String Constant - zogGhLjGW 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
... (truncated)