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

Static analysis result for SHA-256 b1e2b908c994394a…

MALICIOUS

Office (OLE) / .XLS

93.5 KB Created: 2020-05-24 21:15:18 Authoring application: Microsoft Excel
MD5: 07b955318d5edfc185b1fa244caa4d14 SHA-1: b493e08d661d39dce3e58059f9eac33b392ab719 SHA-256: b1e2b908c994394aa930c61705bd589e7b184dbdf1efd97c213332c3f01666fd
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 User Execution: Malicious File T1105 Ingress Tool Transfer

The sample is an Excel workbook containing Excel 4.0 (XLM) macros designed for auto-execution via an Auto_Open entry. Heuristics indicate the use of dangerous formula APIs (RUN=434), which are typically used to execute arbitrary system commands or download payloads. While the document body contains a large amount of obfuscated or randomized text, no clear second-stage URL was reconstructed from the truncated script excerpts provided.

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
605f278b37c0df79aac4f33175d8fff8f397835bba98ac1b45e4e41e5b28cdfe
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 74673 bytes