Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3d5b74f226f3882d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:39 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: 6c4e3d99f6dd1a790478543043efd59f SHA-1: 2f1645e73391dd80d2bb5886e17b6df0e120ba3f SHA-256: 3d5b74f226f3882d66c08f6b1f60d7e2f386a9214dc9e5172880f349bb33f042
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 sheet that contains an Auto_Open defined name, indicating that malicious code will execute automatically when the workbook is opened. The critical heuristic OLE_XLM_DANGEROUS_FN indicates the use of dangerous formula APIs, specifically RUN=0, which is commonly used to execute arbitrary commands or download payloads. No specific URLs or hashes were extracted, but the presence of the Auto_Open macro strongly suggests a downloader or initial execution vector.

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) 6405 bytes
SHA-256: eb5c164b6e1d6a27a8fee5e129349056569b1adf8aeb87788334c452bb957967
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 -  SJpp
' 0018     24 LABEL : Cell Value, String Constant - aTnFlpqQQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F137 
' 0018     22 LABEL : Cell Value, String Constant - BBRzZkR len=0 
' 0018     21 LABEL : Cell Value, String Constant - Bgbsqi len=0 
' 0018     25 LABEL : Cell Value, String Constant - eUGnxnoCkL len=0 
' 0018     27 LABEL : Cell Value, String Constant - gGcleAzHjFQx len=0 
' 0018     25 LABEL : Cell Value, String Constant - giCqgjQCbs len=0 
' 0018     26 LABEL : Cell Value, String Constant - iTueWrUhoeN len=0 
' 0018     25 LABEL : Cell Value, String Constant - lCWLmcSDIP len=0 
' 0018     22 LABEL : Cell Value, String Constant - nOMTcat len=0 
' 0018     20 LABEL : Cell Value, String Constant - NzirY len=0 
' 0018     22 LABEL : Cell Value, String Constant - oCulSvQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - odPhAYgJfk len=0 
' 0018     23 LABEL : Cell Value, String Constant - OPfhvigW len=0 
' 0018     23 LABEL : Cell Value, String Constant - QLAfnCUs len=0 
' 0018     20 LABEL : Cell Value, String Constant - RPLVj len=0 
' 0018     26 LABEL : Cell Value, String Constant - saVjxsOxOGC len=0 
' 0018     23 LABEL : Cell Value, String Constant - UqnpyCWm len=0 
' 0018     20 LABEL : Cell Value, String Constant - vuPNh len=0 
' 0018     25 LABEL : Cell Value, String Constant - ybVEeTLHjG len=0 
' 0018     24 LABEL : Cell Value, String Constant - zKDhdWndt 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 
... (truncated)

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