Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c1dde1d0351e5ed8…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:43:17 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: e4082fa1784cb95fb23ce17bec8f9bf0 SHA-1: b64034eed7a0d7b1c4a8a8a8f69f04df141220c3 SHA-256: c1dde1d0351e5ed8cc203dcf9c6fe51a9011394267b532361f1dadff33aba5fb
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 defined name, which is a critical finding indicating automatic execution upon opening. The macros utilize dangerous formula APIs, including a 'RUN' function, suggesting the execution of external commands. This points to a macro-based downloader or dropper designed to execute a second-stage payload.

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) 6461 bytes
SHA-256: dc7c51c3576991a24bdf475f5e57a171f36eb9f037b49b621f57d8f5e2ceaeb9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  qmjodf
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E149 
' 0018     24 LABEL : Cell Value, String Constant - aYkGXskHU len=0 
' 0018     26 LABEL : Cell Value, String Constant - aZSDzJQtHPG len=0 
' 0018     23 LABEL : Cell Value, String Constant - BHFXLgBG len=0 
' 0018     22 LABEL : Cell Value, String Constant - bOBQEJD len=0 
' 0018     24 LABEL : Cell Value, String Constant - cbhUuQvSA len=0 
' 0018     27 LABEL : Cell Value, String Constant - DCjFGqcskacA len=0 
' 0018     20 LABEL : Cell Value, String Constant - dXrjS len=0 
' 0018     20 LABEL : Cell Value, String Constant - eecck len=0 
' 0018     22 LABEL : Cell Value, String Constant - fDJxCVZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - fJtCUkLYi len=0 
' 0018     24 LABEL : Cell Value, String Constant - GItycsmzU len=0 
' 0018     23 LABEL : Cell Value, String Constant - irqHHpsV len=0 
' 0018     26 LABEL : Cell Value, String Constant - kBtCatGSfyW len=0 
' 0018     24 LABEL : Cell Value, String Constant - KqSRZiRCF len=0 
' 0018     26 LABEL : Cell Value, String Constant - lojzbrpILPu len=0 
' 0018     21 LABEL : Cell Value, String Constant - pmMXVH len=0 
' 0018     22 LABEL : Cell Value, String Constant - TxvnHbv len=0 
' 0018     22 LABEL : Cell Value, String Constant - UAYZVlF len=0 
' 0018     25 LABEL : Cell Value, String Constant - UmJupkJfIz len=0 
' 0018     24 LABEL : Cell Value, String Constant - XWCeHSXDI 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)

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