Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6d3c398c79f2f1d1…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:29:08 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 9f21712493fef77d16bdb456351d7020 SHA-1: 1a2c665d663192571dc6969b1979f5fe8378e372 SHA-256: 6d3c398c79f2f1d1d13d29c8383b5aa063bd02a0f9949319a47433c798d74ef0
140 Risk Score

Malware Insights

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

This Excel file contains Excel 4.0 (XLM) macros, specifically triggering an Auto_Open function. This function is known to be used to execute arbitrary code, often to download and run further malicious content. The presence of dangerous formula APIs like RUN further supports this malicious intent.

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) 6498 bytes
SHA-256: fa79e77f5e2bf7d1639cd0e7fd1821a1a687303072cf2c5b8299f78fa4c129c7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  pXNZtx
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C173 
' 0018     20 LABEL : Cell Value, String Constant - ckmeY len=0 
' 0018     26 LABEL : Cell Value, String Constant - eABQSDnfVGf len=0 
' 0018     27 LABEL : Cell Value, String Constant - fBMAaQVOSHix len=0 
' 0018     27 LABEL : Cell Value, String Constant - ffTJHglULwip len=0 
' 0018     27 LABEL : Cell Value, String Constant - GgZCNRdTxYNJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - HLLlLhgBI len=0 
' 0018     27 LABEL : Cell Value, String Constant - mwQATgiGGARr len=0 
' 0018     26 LABEL : Cell Value, String Constant - NQPoSdLzdRw len=0 
' 0018     27 LABEL : Cell Value, String Constant - ocJTTlUhYqUH len=0 
' 0018     26 LABEL : Cell Value, String Constant - oizmhPkBcfX len=0 
' 0018     20 LABEL : Cell Value, String Constant - oXkbk len=0 
' 0018     24 LABEL : Cell Value, String Constant - pgBLRDQOu len=0 
' 0018     23 LABEL : Cell Value, String Constant - RldWmTDD len=0 
' 0018     21 LABEL : Cell Value, String Constant - rvCvbJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - TLVFMg len=0 
' 0018     22 LABEL : Cell Value, String Constant - UAhwkgx len=0 
' 0018     25 LABEL : Cell Value, String Constant - uOpocRiZtL len=0 
' 0018     25 LABEL : Cell Value, String Constant - vdkNpRPRVu len=0 
' 0018     20 LABEL : Cell Value, String Constant - VYOSF len=0 
' 0018     24 LABEL : Cell Value, String Constant - wVABIPepv 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/ SS
... (truncated)

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