Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a97cdd39e565192…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:43:54 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: dfad34342dc6ed95fe2d8915cd46a947 SHA-1: a8f318ecc646b7abd8aad8f676a8a0fc635c3cdd SHA-256: 3a97cdd39e565192038047fbf8734516a8bb5165ccb498e279b7c65d8855377d
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 containing an Auto_Open function, which is a common technique for executing malicious code upon opening. The presence of dangerous formula APIs in the Auto_Open macro suggests an intent to run arbitrary commands or download further payloads. No specific family could be identified.

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) 6399 bytes
SHA-256: dd9cb7711bef541e528e9ec09357cdf822550554203c4b34cee0b5acf9357662
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  yle
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I167 
' 0018     25 LABEL : Cell Value, String Constant - BrWmyELLAq len=0 
' 0018     27 LABEL : Cell Value, String Constant - CjWZhRvmMpgm len=0 
' 0018     22 LABEL : Cell Value, String Constant - fJGScVA len=0 
' 0018     20 LABEL : Cell Value, String Constant - InOif len=0 
' 0018     22 LABEL : Cell Value, String Constant - iXXxGmP len=0 
' 0018     27 LABEL : Cell Value, String Constant - IzMQmQZoBFBr len=0 
' 0018     26 LABEL : Cell Value, String Constant - kBChNnnrXdB len=0 
' 0018     24 LABEL : Cell Value, String Constant - ljPlqoihM len=0 
' 0018     25 LABEL : Cell Value, String Constant - nGxWdKGUpo len=0 
' 0018     22 LABEL : Cell Value, String Constant - NHJFGZY len=0 
' 0018     26 LABEL : Cell Value, String Constant - OulVxLYTZmb len=0 
' 0018     26 LABEL : Cell Value, String Constant - PSeHYeQUvWu len=0 
' 0018     21 LABEL : Cell Value, String Constant - QIsazE len=0 
' 0018     23 LABEL : Cell Value, String Constant - Rqdzymkj len=0 
' 0018     24 LABEL : Cell Value, String Constant - TGsQodWOF len=0 
' 0018     22 LABEL : Cell Value, String Constant - yGMAiZY len=0 
' 0018     21 LABEL : Cell Value, String Constant - ylNmyG len=0 
' 0018     26 LABEL : Cell Value, String Constant - YSrYKupIwcv len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZgrBaHmJpBF len=0 
' 0018     25 LABEL : Cell Value, String Constant - zvoCLyMLxQ 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
' 0
... (truncated)

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