Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 aa058c3c0dabf1dc…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:28 Authoring application: Microsoft Excel First seen: 2021-09-25
MD5: dc27f1f9fb4fe2cc2e2366958eba55f2 SHA-1: 6e0e21ac96f9cb64486b2eade11cd09ffbdfeed9 SHA-256: aa058c3c0dabf1dc7d8b326f15a0a6c2909429cc601ad9d0f03e968e892ffa0d
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating potential malicious execution. The presence of dangerous formula APIs like RUN further supports this. The macro sheet itself contains obfuscated strings and potentially executable code, though the exact payload is not discernible from the provided 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) 6414 bytes
SHA-256: 8ccf1cdb8c313a982a91f9ba8a0be49e308a18f8502b0eb514efb85656529d73
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  aTX
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I174 
' 0018     21 LABEL : Cell Value, String Constant - dyaucA len=0 
' 0018     27 LABEL : Cell Value, String Constant - FGwuwfRCbamL len=0 
' 0018     22 LABEL : Cell Value, String Constant - gkuvvKg len=0 
' 0018     26 LABEL : Cell Value, String Constant - HDuCcilkikB len=0 
' 0018     26 LABEL : Cell Value, String Constant - hOMtSzBlUBO len=0 
' 0018     21 LABEL : Cell Value, String Constant - HRbsmg len=0 
' 0018     24 LABEL : Cell Value, String Constant - JEntZgOMR len=0 
' 0018     26 LABEL : Cell Value, String Constant - KMFwKwXfJft len=0 
' 0018     27 LABEL : Cell Value, String Constant - LuUkApbOoRxw len=0 
' 0018     23 LABEL : Cell Value, String Constant - NtqpPhOQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - pOXCVlXLQgp len=0 
' 0018     21 LABEL : Cell Value, String Constant - vXFybb len=0 
' 0018     22 LABEL : Cell Value, String Constant - WEnzUjO len=0 
' 0018     27 LABEL : Cell Value, String Constant - wQqxFwALeLvl len=0 
' 0018     24 LABEL : Cell Value, String Constant - WwqBdlKsp len=0 
' 0018     22 LABEL : Cell Value, String Constant - WyTrTjN len=0 
' 0018     25 LABEL : Cell Value, String Constant - XDrdksrbXq len=0 
' 0018     27 LABEL : Cell Value, String Constant - xVlqoCTzRxYn len=0 
' 0018     26 LABEL : Cell Value, String Constant - YLyIitobUYo len=0 
' 0018     22 LABEL : Cell Value, String Constant - YuEDFgn 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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