Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b70458d8965b36ef…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:39:32 Authoring application: Microsoft Excel First seen: 2021-11-03
MD5: a468599bce77c39f7ab609da3eed6a78 SHA-1: 106de1301304d2543efc8ff30492287041df4a59 SHA-256: b70458d8965b36efffabca032c56e146059c91aacfbf812de87c932eb6eb2e52
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 known method for executing malicious code. The macro sheet contains a reference to a dangerous formula API, specifically 'RUN', suggesting it's designed to execute commands or payloads. The document body contains a large amount of seemingly random characters, which could be obfuscation or part of a payload.

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) 6622 bytes
SHA-256: e10062e01947cc2039506df38b00dfaef7527d34dd9bba072f231c69168fc62d
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  rSWygz
' 0018     22 LABEL : Cell Value, String Constant - aAejbfa len=0 
' 0018     24 LABEL : Cell Value, String Constant - AIsVuoHTc len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D145 
' 0018     25 LABEL : Cell Value, String Constant - cEGVxSzTBF len=0 
' 0018     22 LABEL : Cell Value, String Constant - dloIcLG len=0 
' 0018     25 LABEL : Cell Value, String Constant - dWHfxeEEVK len=0 
' 0018     21 LABEL : Cell Value, String Constant - elsWoS len=0 
' 0018     24 LABEL : Cell Value, String Constant - FucjrJqHl len=0 
' 0018     27 LABEL : Cell Value, String Constant - gwzwNNrRjcfP len=0 
' 0018     27 LABEL : Cell Value, String Constant - jbxCoJrCDijQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - knqpS len=0 
' 0018     26 LABEL : Cell Value, String Constant - OOFcGlRZnGb len=0 
' 0018     22 LABEL : Cell Value, String Constant - OWPJrDP len=0 
' 0018     24 LABEL : Cell Value, String Constant - pKsiNdxMW len=0 
' 0018     24 LABEL : Cell Value, String Constant - PRXoUEkbb len=0 
' 0018     23 LABEL : Cell Value, String Constant - pyvXzdWm len=0 
' 0018     20 LABEL : Cell Value, String Constant - qcxpa len=0 
' 0018     27 LABEL : Cell Value, String Constant - rHRHzEjEMwKk len=0 
' 0018     24 LABEL : Cell Value, String Constant - WwopMPxOe len=0 
' 0018     25 LABEL : Cell Value, String Constant - XcGzUFStBk len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZcSffaBrWvKf 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
'
... (truncated)

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