Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1cd7a5cb322b9b94…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:35 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: a7e3d9f74fff9b3fa43f0ebdc58d899a SHA-1: f31ee6b8d04acac8f175b7aee11058df84a13857 SHA-256: 1cd7a5cb322b9b94571a2f07415a76c3591449f196e5ad78cfc593803dcc2305
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name, which is a known method for executing malicious code upon opening the workbook. The `RUN` function API is also present, suggesting the macro is designed to execute an external payload. No specific URLs or hashes were extracted, but the technique strongly implies a downloader or dropper functionality.

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) 6774 bytes
SHA-256: d5fbaeff16605f0fbbe6398d4b757e5fd4e55dd0c3287b5536fa35d06e3d26c8
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 -  yUVhxrBqQ
' 0018     25 LABEL : Cell Value, String Constant - ARkKCpeOYG len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F151 
' 0018     21 LABEL : Cell Value, String Constant - eVIPgl len=0 
' 0018     26 LABEL : Cell Value, String Constant - gPnbFmdsyJe len=0 
' 0018     20 LABEL : Cell Value, String Constant - GtFqT len=0 
' 0018     24 LABEL : Cell Value, String Constant - HFJsUfiYA len=0 
' 0018     26 LABEL : Cell Value, String Constant - jtjckDzXUPo len=0 
' 0018     27 LABEL : Cell Value, String Constant - LHLhUNiyQPCB len=0 
' 0018     25 LABEL : Cell Value, String Constant - mCkKLIMYey len=0 
' 0018     20 LABEL : Cell Value, String Constant - mHUxs len=0 
' 0018     25 LABEL : Cell Value, String Constant - oorwQhqacp len=0 
' 0018     20 LABEL : Cell Value, String Constant - oxjlI len=0 
' 0018     27 LABEL : Cell Value, String Constant - QayjRLIrSDjA len=0 
' 0018     20 LABEL : Cell Value, String Constant - sEURN len=0 
' 0018     24 LABEL : Cell Value, String Constant - sMaueRRjW len=0 
' 0018     27 LABEL : Cell Value, String Constant - STqztVFiiwVm len=0 
' 0018     23 LABEL : Cell Value, String Constant - UBxWLkrt len=0 
' 0018     23 LABEL : Cell Value, String Constant - uFPMzFmU len=0 
' 0018     24 LABEL : Cell Value, String Constant - uhMJcYAtR len=0 
' 0018     24 LABEL : Cell Value, String Constant - urcCasboP len=0 
' 0018     21 LABEL : Cell Value, String Constant - Zxjgoz 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
' 00f
... (truncated)

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