Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6229cf9ed96171ea…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:24 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 9e5fb7725dc44c0ab9a5868a80ef4bff SHA-1: 7842d8b257597e5370c9b3012a6fb5f6786a9ecb SHA-256: 6229cf9ed96171ea6cda2d4ed4d1e78496222cfaea6a85f6bf55ff481ef3e042
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 entry point, which is a known method for executing malicious code. The macro sheet contains formulas that can call dangerous APIs, including the RUN function, suggesting it's designed to execute arbitrary commands. The extensive obfuscated data in the document body likely contains the payload or further instructions 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) 6834 bytes
SHA-256: e9040b5b3a4a99c1ce4e8e5657598038b18c7a0cce82a634af22b39bc0704c9c
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 -  UXMCgSDjMO
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H132 
' 0018     27 LABEL : Cell Value, String Constant - azmSFCTwbQGg len=0 
' 0018     23 LABEL : Cell Value, String Constant - cHCUIHuu len=0 
' 0018     21 LABEL : Cell Value, String Constant - ChEaQc len=0 
' 0018     26 LABEL : Cell Value, String Constant - CrWQHVLRPSi len=0 
' 0018     24 LABEL : Cell Value, String Constant - CtMqLMKTD len=0 
' 0018     21 LABEL : Cell Value, String Constant - emNKIq len=0 
' 0018     20 LABEL : Cell Value, String Constant - foAoK len=0 
' 0018     25 LABEL : Cell Value, String Constant - fWFSwzoQzn len=0 
' 0018     23 LABEL : Cell Value, String Constant - IISlpwFo len=0 
' 0018     21 LABEL : Cell Value, String Constant - KZSryx len=0 
' 0018     20 LABEL : Cell Value, String Constant - MNzTE len=0 
' 0018     24 LABEL : Cell Value, String Constant - oWBgEjVpE len=0 
' 0018     22 LABEL : Cell Value, String Constant - qFhhxtG len=0 
' 0018     23 LABEL : Cell Value, String Constant - RQsnUsfD len=0 
' 0018     23 LABEL : Cell Value, String Constant - RUEVQhqR len=0 
' 0018     27 LABEL : Cell Value, String Constant - uOmnyBhrpZvy len=0 
' 0018     25 LABEL : Cell Value, String Constant - vsqavDudOi len=0 
' 0018     26 LABEL : Cell Value, String Constant - wfzorjEPgio len=0 
' 0018     25 LABEL : Cell Value, String Constant - YymBXwAggC len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZWoLeQWkDeQi 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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