Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 20599181b8720b8e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:46:28 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: 6625fe1d38a8495b598129d4134871da SHA-1: f0873947b1f259769a6949009167f93a707659a7 SHA-256: 20599181b8720b8e7a50b85ea18fdcf1ef3831ece53a071749e6562c6f269d4e
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 critical heuristic firings indicate the presence of dangerous formula APIs, including a RUN function, suggesting the macro is designed to execute arbitrary commands. No specific family could be identified, and no further 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) 6627 bytes
SHA-256: c17b1d885aff30b3081bd50bc5547cf0ba51dca090cdc5776b603c9f60e3f058
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  JPdhF
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D168 
' 0018     22 LABEL : Cell Value, String Constant - DNWuAKW len=0 
' 0018     22 LABEL : Cell Value, String Constant - eGmDbFH len=0 
' 0018     21 LABEL : Cell Value, String Constant - eyRLKn len=0 
' 0018     27 LABEL : Cell Value, String Constant - FtZuDyqyFTor len=0 
' 0018     24 LABEL : Cell Value, String Constant - gAysRrchI len=0 
' 0018     22 LABEL : Cell Value, String Constant - GRYqfvw len=0 
' 0018     21 LABEL : Cell Value, String Constant - jEsVUx len=0 
' 0018     22 LABEL : Cell Value, String Constant - JnrwIDC len=0 
' 0018     23 LABEL : Cell Value, String Constant - KiyeqxzS len=0 
' 0018     26 LABEL : Cell Value, String Constant - lKLFHbDVgPm len=0 
' 0018     24 LABEL : Cell Value, String Constant - MAwzwcVWN len=0 
' 0018     26 LABEL : Cell Value, String Constant - nWEvJexDath len=0 
' 0018     24 LABEL : Cell Value, String Constant - qCTXPqtGW len=0 
' 0018     21 LABEL : Cell Value, String Constant - tYgoHn len=0 
' 0018     26 LABEL : Cell Value, String Constant - vDoNuHrUYla len=0 
' 0018     24 LABEL : Cell Value, String Constant - xbOCZgTKX len=0 
' 0018     22 LABEL : Cell Value, String Constant - XLTOdkM len=0 
' 0018     27 LABEL : Cell Value, String Constant - YTeErHVHWahi len=0 
' 0018     23 LABEL : Cell Value, String Constant - zFTIuyDB len=0 
' 0018     21 LABEL : Cell Value, String Constant - zzeQqY 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
... (truncated)

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