Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8aff9fb3250d7e7f…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:33:49 Authoring application: Microsoft Excel First seen: 2021-09-27
MD5: ae28be6671cde6af197d28f27767d887 SHA-1: 29edc6a336c09e6eba7216042411268f17409efa SHA-256: 8aff9fb3250d7e7f90aa5594a1856b5234548ddc76a82e5d328b493a1c14ab86
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 document detected with critical heuristics for Auto_Open functionality and the use of dangerous formula APIs like RUN. This indicates the macro is designed to execute arbitrary code upon opening, a common technique for downloading and executing further malicious payloads. No specific family could be identified from the available evidence.

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) 6453 bytes
SHA-256: 4a847bea99c645dc4a17a93103df4fddf87c32334cacb263730353e954b19589
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 -  uCVT
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C162 
' 0018     24 LABEL : Cell Value, String Constant - bYpjuCZkm len=0 
' 0018     27 LABEL : Cell Value, String Constant - DsTCcfnHVJjH len=0 
' 0018     26 LABEL : Cell Value, String Constant - etheQSEwZfo len=0 
' 0018     20 LABEL : Cell Value, String Constant - EXXFX len=0 
' 0018     21 LABEL : Cell Value, String Constant - FOrFKS len=0 
' 0018     22 LABEL : Cell Value, String Constant - fzdwoMe len=0 
' 0018     23 LABEL : Cell Value, String Constant - jHYHUiDM len=0 
' 0018     20 LABEL : Cell Value, String Constant - koHjS len=0 
' 0018     22 LABEL : Cell Value, String Constant - MvmtZBJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - nIQHxRgbBI len=0 
' 0018     24 LABEL : Cell Value, String Constant - nwlDSuUFM len=0 
' 0018     20 LABEL : Cell Value, String Constant - oveXI len=0 
' 0018     26 LABEL : Cell Value, String Constant - sDiDUGTpRpV len=0 
' 0018     21 LABEL : Cell Value, String Constant - SzaqoH len=0 
' 0018     22 LABEL : Cell Value, String Constant - UyLjwrh len=0 
' 0018     23 LABEL : Cell Value, String Constant - vbVgzUHn len=0 
' 0018     21 LABEL : Cell Value, String Constant - XkLGHn len=0 
' 0018     23 LABEL : Cell Value, String Constant - XOlcmqsO len=0 
' 0018     24 LABEL : Cell Value, String Constant - zfMVyKcxg len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZUWDnsgiJLbu 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 LABELSS
... (truncated)

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