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

Static analysis result for SHA-256 91ece151fbb676ca…

MALICIOUS

Office (OLE) / .XLS

367.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: a58a991630ad636704954d149513b717 SHA-1: e5dc70e5933288ebbf2c9a2119cb173c14a17bfb SHA-256: 91ece151fbb676ca78f2d72547c1610662f3089d6fe8c122b467bdd9004d7221
102 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro, indicating it will execute automatically when the file is opened. The document body and heuristics suggest a lure to enable macros. The XLM macro sheet contains concatenated strings that appear to form URLs, which are likely used to download a second-stage payload. The presence of an Auto_Open macro and the macro-enable lure strongly suggest a malicious intent to execute arbitrary code.

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