Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 212284afaf945fbe…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:46:21 Authoring application: Microsoft Excel First seen: 2021-10-11
MD5: 8114bf8f262918452bdb9ef67a456612 SHA-1: 44c5594e75843fe648d37fa3d4e1256d4901055c SHA-256: 212284afaf945fbee21600adf3a18beb3e891947fcb2b400d559b1dac24bc61f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name, which is a common technique for executing malicious code upon opening the document. The macro sheet itself contains obfuscated data, suggesting an attempt to hide its true functionality. The Auto_Open entry points to an initial execution vector via spearphishing attachment.

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) 6591 bytes
SHA-256: ca718966397632026a909a0beaed684c34714c1748d911c6ed73be95081f8bae
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 -  lYjc
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E159 
' 0018     25 LABEL : Cell Value, String Constant - bedJxyrCuu len=0 
' 0018     21 LABEL : Cell Value, String Constant - BkTUSl len=0 
' 0018     26 LABEL : Cell Value, String Constant - chraJDgLfrL len=0 
' 0018     20 LABEL : Cell Value, String Constant - DqAkW len=0 
' 0018     24 LABEL : Cell Value, String Constant - dwHzGTuUR len=0 
' 0018     26 LABEL : Cell Value, String Constant - ECFCZyxuzVw len=0 
' 0018     24 LABEL : Cell Value, String Constant - FvvSZrsoB len=0 
' 0018     23 LABEL : Cell Value, String Constant - GCkErBGS len=0 
' 0018     22 LABEL : Cell Value, String Constant - gHHpkuw len=0 
' 0018     22 LABEL : Cell Value, String Constant - HJmKsbB len=0 
' 0018     21 LABEL : Cell Value, String Constant - JunUun len=0 
' 0018     22 LABEL : Cell Value, String Constant - LlXaSNJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - LvSBf len=0 
' 0018     22 LABEL : Cell Value, String Constant - pkvSEZY len=0 
' 0018     22 LABEL : Cell Value, String Constant - pvvsaxZ len=0 
' 0018     26 LABEL : Cell Value, String Constant - QDzNpykjzaY len=0 
' 0018     23 LABEL : Cell Value, String Constant - QUuYqoHS len=0 
' 0018     27 LABEL : Cell Value, String Constant - VmqUfyfkkVQB len=0 
' 0018     23 LABEL : Cell Value, String Constant - WKUQVFvQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - wQiCyioxYHz 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 LAB
... (truncated)

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