Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ff24f4e49f427718…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:45 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: 699a2e425555230d39881dbc57346dfb SHA-1: bd75d30472299c7fff644b105eb085d0bf0e7188 SHA-256: ff24f4e49f4277189fc7ba2c51a5ec059b1b288f9e8ddf6b074080b69470d45a
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open function. This function is designed to automatically execute when the workbook is opened, indicating an attempt to run arbitrary code. The presence of dangerous formula APIs further supports the malicious intent.

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) 6731 bytes
SHA-256: d408d0baaeb2c1619707fe33e558679f63c033983c4ff8ef6c865578e06543d1
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  iGXlbYpq
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C148 
' 0018     20 LABEL : Cell Value, String Constant - dwIaa len=0 
' 0018     23 LABEL : Cell Value, String Constant - FhPrPQLR len=0 
' 0018     27 LABEL : Cell Value, String Constant - fKEwXDFLbLMZ len=0 
' 0018     26 LABEL : Cell Value, String Constant - fxLfvCrYOhl len=0 
' 0018     24 LABEL : Cell Value, String Constant - HVMipuYff len=0 
' 0018     22 LABEL : Cell Value, String Constant - inFjlAu len=0 
' 0018     24 LABEL : Cell Value, String Constant - nkWNtBSLM len=0 
' 0018     23 LABEL : Cell Value, String Constant - OXVbbpbc len=0 
' 0018     22 LABEL : Cell Value, String Constant - rbwQnuN len=0 
' 0018     23 LABEL : Cell Value, String Constant - risGPtUy len=0 
' 0018     20 LABEL : Cell Value, String Constant - rnqmq len=0 
' 0018     24 LABEL : Cell Value, String Constant - tonpfGssj len=0 
' 0018     26 LABEL : Cell Value, String Constant - TQqHAxpMLxz len=0 
' 0018     27 LABEL : Cell Value, String Constant - TrKknpVAhedj len=0 
' 0018     21 LABEL : Cell Value, String Constant - tTIJPw len=0 
' 0018     27 LABEL : Cell Value, String Constant - VsahjdBmzPLj len=0 
' 0018     20 LABEL : Cell Value, String Constant - wXzuS len=0 
' 0018     25 LABEL : Cell Value, String Constant - XxGjHrwBqV len=0 
' 0018     21 LABEL : Cell Value, String Constant - YBZkEt len=0 
' 0018     24 LABEL : Cell Value, String Constant - yTssacrNj 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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