Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f3828cbcc130f4b7…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:41:40 Authoring application: Microsoft Excel First seen: 2021-10-02
MD5: 6cfc5550ecdbfac8e4bb908b78b51d9b SHA-1: f206b09ef8424714ac6572b67706d3dfc74c2516 SHA-256: f3828cbcc130f4b7594da6469e11543d904f49b5316502f8559756ce0d10fd7f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, specifically using dangerous formula APIs like RUN. This suggests the file is designed to execute arbitrary code when opened, likely as a malicious attachment delivered via spearphishing. No specific IOCs like URLs or hashes were extracted from the macro content itself.

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) 6854 bytes
SHA-256: 385d6c670f2b893cf934add7f996fca5d68bfdbb4044096e7439e12e995aa790
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  gmtprzMtQqI
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B195 
' 0018     24 LABEL : Cell Value, String Constant - CYBHxpXQD len=0 
' 0018     21 LABEL : Cell Value, String Constant - GvnifU len=0 
' 0018     24 LABEL : Cell Value, String Constant - gwPIAAFYc len=0 
' 0018     20 LABEL : Cell Value, String Constant - hjbWx len=0 
' 0018     20 LABEL : Cell Value, String Constant - IfYBX len=0 
' 0018     25 LABEL : Cell Value, String Constant - KvHxSDqthd len=0 
' 0018     24 LABEL : Cell Value, String Constant - MGlDBkOiT len=0 
' 0018     27 LABEL : Cell Value, String Constant - oCeejqZLVdiI len=0 
' 0018     25 LABEL : Cell Value, String Constant - qqudhDuYHf len=0 
' 0018     26 LABEL : Cell Value, String Constant - RFQaZQOIhMg len=0 
' 0018     23 LABEL : Cell Value, String Constant - rWmIdsMZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - UIUHoPNmuV len=0 
' 0018     20 LABEL : Cell Value, String Constant - umWtV len=0 
' 0018     24 LABEL : Cell Value, String Constant - vCMxNymtj len=0 
' 0018     20 LABEL : Cell Value, String Constant - WoCWt len=0 
' 0018     26 LABEL : Cell Value, String Constant - XJLgSviEcJn len=0 
' 0018     20 LABEL : Cell Value, String Constant - XpQuu len=0 
' 0018     23 LABEL : Cell Value, String Constant - YqgttcHm len=0 
' 0018     21 LABEL : Cell Value, String Constant - YQuHgW len=0 
' 0018     23 LABEL : Cell Value, String Constant - yZxeiRtL 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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