Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 642cd10fc3dded11…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:43:40 Authoring application: Microsoft Excel First seen: 2021-10-12
MD5: 054330f2e2eccc52eecae0d5ba3ab880 SHA-1: e205665ee0f14facc5b386d5a68b999cecc8f2e4 SHA-256: 642cd10fc3dded114726c47be6d44e7f37eeb423d30d6081fbe2f8c8918977e9
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 function, which is a known technique for executing malicious code upon opening the workbook. The heuristics indicate the use of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to run arbitrary commands. No specific family could be identified, but the technique points to a macro-based downloader or executioner.

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) 6772 bytes
SHA-256: 7c1035b606aa974a88f07541c512f26b6155535df55e0b6a493071f1e6e03e07
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  zYILRLT
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I149 
' 0018     21 LABEL : Cell Value, String Constant - boAgLU len=0 
' 0018     26 LABEL : Cell Value, String Constant - FfJQNhVXFyg len=0 
' 0018     25 LABEL : Cell Value, String Constant - fzMQjYmtut len=0 
' 0018     27 LABEL : Cell Value, String Constant - GmsLzXeyQhlt len=0 
' 0018     26 LABEL : Cell Value, String Constant - IFevTiZadDH len=0 
' 0018     23 LABEL : Cell Value, String Constant - kNsaDMTz len=0 
' 0018     26 LABEL : Cell Value, String Constant - LoFsKDIlqon len=0 
' 0018     23 LABEL : Cell Value, String Constant - lTqXwYoK len=0 
' 0018     24 LABEL : Cell Value, String Constant - mdXExxTxh len=0 
' 0018     21 LABEL : Cell Value, String Constant - qRAteR len=0 
' 0018     25 LABEL : Cell Value, String Constant - QyabiLHRGw len=0 
' 0018     24 LABEL : Cell Value, String Constant - rheAyMIqr len=0 
' 0018     23 LABEL : Cell Value, String Constant - RPYQMCQk len=0 
' 0018     25 LABEL : Cell Value, String Constant - stxFIuaGRu len=0 
' 0018     27 LABEL : Cell Value, String Constant - TRoHRlylshFi len=0 
' 0018     23 LABEL : Cell Value, String Constant - TZCFhWZn len=0 
' 0018     24 LABEL : Cell Value, String Constant - vWrsUmicw len=0 
' 0018     22 LABEL : Cell Value, String Constant - wTNCvoW len=0 
' 0018     21 LABEL : Cell Value, String Constant - XjgyOn len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZQGYWo 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
' 
... (truncated)

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