Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4dfdf9ee17bf74bb…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:25:54 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 3a241eab5c9881100e5116f693badf62 SHA-1: 53c08f31d1a3cdb574710cea2350cfe1fd09d639 SHA-256: 4dfdf9ee17bf74bbddddc427cc9bd90a0753fe99ea3fedd4a430b3f2d8a246ab
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open function, which is a common technique for executing malicious code upon opening the workbook. The macro sheet contains a dangerous formula API call, suggesting it is designed to download and execute a secondary payload.

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) 6355 bytes
SHA-256: 751c0bf8d8a9f7a7d1b8626984f8e96ee7b9e5e207812eb1010602d9c4084b08
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  QRZF
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G148 
' 0018     23 LABEL : Cell Value, String Constant - coTITUYD len=0 
' 0018     22 LABEL : Cell Value, String Constant - gAkRrJD len=0 
' 0018     22 LABEL : Cell Value, String Constant - gMTrDke len=0 
' 0018     21 LABEL : Cell Value, String Constant - HGQAYG len=0 
' 0018     20 LABEL : Cell Value, String Constant - Irrtx len=0 
' 0018     24 LABEL : Cell Value, String Constant - KXIiPKDvK len=0 
' 0018     25 LABEL : Cell Value, String Constant - mvRQNbvWJY len=0 
' 0018     21 LABEL : Cell Value, String Constant - OOShPp len=0 
' 0018     26 LABEL : Cell Value, String Constant - OoswUMnKfRJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - PvrhmCDTuFc len=0 
' 0018     22 LABEL : Cell Value, String Constant - RBoqHhp len=0 
' 0018     23 LABEL : Cell Value, String Constant - SlzYnArO len=0 
' 0018     22 LABEL : Cell Value, String Constant - vkYQOKf len=0 
' 0018     21 LABEL : Cell Value, String Constant - vvcydL len=0 
' 0018     22 LABEL : Cell Value, String Constant - VYTkNCr len=0 
' 0018     21 LABEL : Cell Value, String Constant - weNyAn len=0 
' 0018     21 LABEL : Cell Value, String Constant - YbbEwp len=0 
' 0018     25 LABEL : Cell Value, String Constant - YPuZhvcmJO len=0 
' 0018     20 LABEL : Cell Value, String Constant - zFdlD len=0 
' 0018     23 LABEL : Cell Value, String Constant - zKUXZcFa 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     10 LABELSST : Cell Va
... (truncated)

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