Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 39f595934cae3334…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:55 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 342159723b494caaa25837b7c17dbb41 SHA-1: ff567beabbda243dea99eefe1921f014f2155a02 SHA-256: 39f595934cae33349114e32c18a7fc4337250d0b5c55ba256a85e85615d58cf6
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The macro likely attempts to download and execute a secondary payload, as suggested by the critical heuristic firing for dangerous formula APIs like RUN.

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) 6651 bytes
SHA-256: 2b5ef6a76029d0276df347b3b8c4f6707cee185d6f2fc42f671c68c15379d749
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ZJIZLithpy
' 0018     27 LABEL : Cell Value, String Constant - almOEvxgbnyj len=0 
' 0018     25 LABEL : Cell Value, String Constant - atXeaoQBlK len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E131 
' 0018     25 LABEL : Cell Value, String Constant - BDJlfIFuFG len=0 
' 0018     26 LABEL : Cell Value, String Constant - fydCGPUDmaI len=0 
' 0018     26 LABEL : Cell Value, String Constant - GcmXvqgFKEG len=0 
' 0018     24 LABEL : Cell Value, String Constant - IZbYXGsga len=0 
' 0018     25 LABEL : Cell Value, String Constant - JMzoZLbDie len=0 
' 0018     24 LABEL : Cell Value, String Constant - KaCeuidkd len=0 
' 0018     27 LABEL : Cell Value, String Constant - lqHsDdgyYJXK len=0 
' 0018     26 LABEL : Cell Value, String Constant - MFMYfeobUzI len=0 
' 0018     20 LABEL : Cell Value, String Constant - MHuya len=0 
' 0018     26 LABEL : Cell Value, String Constant - RVVEjvHDsAT len=0 
' 0018     25 LABEL : Cell Value, String Constant - RWbdkPEOez len=0 
' 0018     21 LABEL : Cell Value, String Constant - tCzOjr len=0 
' 0018     21 LABEL : Cell Value, String Constant - UBcuog len=0 
' 0018     22 LABEL : Cell Value, String Constant - uCPdVXk len=0 
' 0018     26 LABEL : Cell Value, String Constant - urBpTOSEiNZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - XchHCZjAl len=0 
' 0018     23 LABEL : Cell Value, String Constant - xCsFvdqb len=0 
' 0018     24 LABEL : Cell Value, String Constant - ztJCSukSU 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 Con
... (truncated)

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