Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 7d242b8c6f41717c…

MALICIOUS

Office (OLE) / .XLS

50.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 0878ac913070df6b8c7fbe45b35baadd SHA-1: a9375cadc6d85ae898a2692069852cd28ab5ebaf SHA-256: 7d242b8c6f41717c953526495b1f702849846c56338c179fbb78df07ba498674
222 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, including an Auto_Open function, which is a known technique for executing malicious code. The macro is designed to download a payload from the URL http://staging.stikbot.toys/24.gif. The presence of a macro-enable lure further supports the malicious intent.

Heuristics 6

  • 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.
  • URL reconstructed from XLM cell array (1 URL) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://staging.stikbot.toys/24.gifDa
    • http://staging.stikbot.toys/24.gif�
    • http://staging.stikbot.toys/24.gif

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
b85a04030ee15a5823afbe8a5c58782f7c760714b2f75fcf902d376138ea1320
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2772 bytes