Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bb3fd995de906924…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:41:49 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: f918484dedbbbc8ff4185eafd5b354ad SHA-1: f0ec3423542d2ac6d273aac7706daacc194e51b7 SHA-256: bb3fd995de906924eeddb19c2bcefa6beecad62211964132e590b7fa0308a03a
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open function, which is a common method for executing malicious code upon opening the document. The macro sheet contains dangerous formula APIs, suggesting it's designed to run arbitrary commands or download further payloads.

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) 6742 bytes
SHA-256: 16abf40eba54894ee3b13975283857a97f04c2c2c8a3e40f5429336279015871
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 -  IGEJfALB
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G174 
' 0018     24 LABEL : Cell Value, String Constant - dgYbxNsMG len=0 
' 0018     20 LABEL : Cell Value, String Constant - ePXqX len=0 
' 0018     24 LABEL : Cell Value, String Constant - fEFITptgh len=0 
' 0018     22 LABEL : Cell Value, String Constant - hztPETW len=0 
' 0018     21 LABEL : Cell Value, String Constant - JtCBdv len=0 
' 0018     26 LABEL : Cell Value, String Constant - jtOuuvEavpK len=0 
' 0018     23 LABEL : Cell Value, String Constant - LghRmGZk len=0 
' 0018     26 LABEL : Cell Value, String Constant - lYjNUAqZuzz len=0 
' 0018     26 LABEL : Cell Value, String Constant - MyyquXDSbmY len=0 
' 0018     27 LABEL : Cell Value, String Constant - nZolKzKvLHFs len=0 
' 0018     22 LABEL : Cell Value, String Constant - QTmWZTR len=0 
' 0018     27 LABEL : Cell Value, String Constant - rzRKVGIdASOA len=0 
' 0018     22 LABEL : Cell Value, String Constant - Slqjgnp len=0 
' 0018     23 LABEL : Cell Value, String Constant - swJRIrKS len=0 
' 0018     24 LABEL : Cell Value, String Constant - uUpvYSSXC len=0 
' 0018     23 LABEL : Cell Value, String Constant - viKMxmzc len=0 
' 0018     20 LABEL : Cell Value, String Constant - XQoVs len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZgDVXlC len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZLrXM len=0 
' 0018     27 LABEL : Cell Value, String Constant - zXBalajkPwjA 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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