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

Static analysis result for SHA-256 17a5d643728c9e1f…

MALICIOUS

Office (OLE) / .XLS

367.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 45bef33cd9aab15a2ce8455c4992e562 SHA-1: 5a447c804c0f94b96271914850b4fc1f5c4eabef SHA-256: 17a5d643728c9e1ff0903c287e4d441d32dafab7d08b2bcecf0eb9561ea58cd0
102 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, including an Auto_Open entry, which is a strong indicator of malicious intent. The presence of a 'Macro/content-enable lure' heuristic suggests the document is designed to prompt the user to enable macros. The XLM macros likely download a second-stage payload from one of the embedded URLs, such as https://escolamundoazul.com.br/ntmQmwXnc6KC/ue.html.

Heuristics 4

  • 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.
  • 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 https://escolamundoazul.com.br/ntmQmwXnc6KC/ue.html
    • https://laresumeservice.com/wp7rTKrY/ue.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e0f9b32b2cf7d5bbad99732afb6eb8bf95619170305ebee6a87504bc690cca2a
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8209 bytes