Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 dc8a5077d9446ecb…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:39:20 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: 730834fe492f3fbe661d04c7dd1fc3e0 SHA-1: 85d6da69eaf6fa0550fa42341d49492c126fd698 SHA-256: dc8a5077d9446ecb8cbfcbce2def82a025022ccf9f0b4e95851e0809dc2b8438
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of an Excel 4.0 macro sheet with an Auto_Open defined name, which is a common technique for executing malicious code upon opening the document. The macro sheet contains dangerous formula APIs, specifically referencing 'RUN=0', suggesting it is designed to execute arbitrary commands. No specific family could be identified, and no external 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) 6619 bytes
SHA-256: 076b80605165d9f75518d6a92ea64cd5b5c7cd581067cf2f9837756be4e82eb0
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 -  TsDcFaGjX
' 0018     25 LABEL : Cell Value, String Constant - ASnxAuueMJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D177 
' 0018     23 LABEL : Cell Value, String Constant - BFSKUCnr len=0 
' 0018     20 LABEL : Cell Value, String Constant - byZcv len=0 
' 0018     20 LABEL : Cell Value, String Constant - cnwlZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - CslhXnIv len=0 
' 0018     23 LABEL : Cell Value, String Constant - DAEtJKem len=0 
' 0018     23 LABEL : Cell Value, String Constant - DkFYzbGw len=0 
' 0018     23 LABEL : Cell Value, String Constant - DWdHZmTs len=0 
' 0018     25 LABEL : Cell Value, String Constant - HAjeyUFrnY len=0 
' 0018     24 LABEL : Cell Value, String Constant - iebFynHBP len=0 
' 0018     27 LABEL : Cell Value, String Constant - jVaisGZbWFlH len=0 
' 0018     25 LABEL : Cell Value, String Constant - mdYIEYUyDT len=0 
' 0018     23 LABEL : Cell Value, String Constant - MFxSdUmb len=0 
' 0018     24 LABEL : Cell Value, String Constant - mMsDCUKlw len=0 
' 0018     23 LABEL : Cell Value, String Constant - NIWrINWB len=0 
' 0018     21 LABEL : Cell Value, String Constant - QSNKiv len=0 
' 0018     20 LABEL : Cell Value, String Constant - rIvEO len=0 
' 0018     21 LABEL : Cell Value, String Constant - rTgRbi len=0 
' 0018     23 LABEL : Cell Value, String Constant - zTwEjNCA len=0 
' 0018     22 LABEL : Cell Value, String Constant - zUKjYpf 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 LABEL
... (truncated)

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