Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2fdc86211927192c…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:36:59 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: a9ca936477addb0542c7a8f10a9de918 SHA-1: 375f4bc17649bbe6ed44b2de00cd019ac74c71d6 SHA-256: 2fdc86211927192c97209882497cd26ccc2845e002da7de3746ff04dc315c6dd
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 common technique for executing malicious code upon opening the document. The macro sheet contains a reference to a dangerous formula API, suggesting it's designed to perform harmful actions. The specific function 'Auto_Open' is identified as the entry point for execution.

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) 6634 bytes
SHA-256: c73d291e42764c2c959eae95de3164f8b88128db6c272b23f15dda2052aa92d3
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  PDyBCizdMMc
' 0018     27 LABEL : Cell Value, String Constant - AALSGGyVBFDJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B158 
' 0018     22 LABEL : Cell Value, String Constant - cfWjvlb len=0 
' 0018     20 LABEL : Cell Value, String Constant - DBpIG len=0 
' 0018     25 LABEL : Cell Value, String Constant - eLwylvjPcM len=0 
' 0018     26 LABEL : Cell Value, String Constant - EsaVwFNERDq len=0 
' 0018     22 LABEL : Cell Value, String Constant - fWjQDJh len=0 
' 0018     27 LABEL : Cell Value, String Constant - fyfGbMnSAKQp len=0 
' 0018     23 LABEL : Cell Value, String Constant - hviPzYYr len=0 
' 0018     23 LABEL : Cell Value, String Constant - iWClvPkz len=0 
' 0018     23 LABEL : Cell Value, String Constant - jQHktfbm len=0 
' 0018     23 LABEL : Cell Value, String Constant - lTwFNkbB len=0 
' 0018     26 LABEL : Cell Value, String Constant - mykIBaeKGIH len=0 
' 0018     20 LABEL : Cell Value, String Constant - nAAxi len=0 
' 0018     27 LABEL : Cell Value, String Constant - RtEXvLitGKwE len=0 
' 0018     21 LABEL : Cell Value, String Constant - tMahmb len=0 
' 0018     24 LABEL : Cell Value, String Constant - UreskSvjR len=0 
' 0018     22 LABEL : Cell Value, String Constant - VZevFFS len=0 
' 0018     23 LABEL : Cell Value, String Constant - xhcBfzCp len=0 
' 0018     23 LABEL : Cell Value, String Constant - zkdEoJOj len=0 
' 0018     21 LABEL : Cell Value, String Constant - zlQpge 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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