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

Static analysis result for SHA-256 0f5dac859b058b1e…

MALICIOUS

Office (OLE) / .XLS

380.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 8c8593ad0b4e3154f74530f2df54f20d SHA-1: 213f896dc9a08fda3598311a8a48bab899139342 SHA-256: 0f5dac859b058b1e2d2e63f75eb848de6004a947387eb14f993c7e6b7e2bbc97
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1204.002 Malicious File

The sample is an Excel file containing Excel 4.0 macros, indicated by the OLE_XLM_AUTOOPEN heuristic. The macros are designed to execute automatically upon opening, as evidenced by the Auto_Open defined name. The document body and extracted URLs suggest a download and execution chain, likely involving the URLs to fetch a second-stage payload. The presence of 'rundll32.exe' and 'regsvr32.exe' in the macro output further supports the execution of downloaded 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://caiogabriel.com.br/tOKLlSLW/lena.html
    • https://bwctradex.com/BcotoLXTr1y/lena.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
d46ad6b52df62d280ddc3eb28f4fdfc78bc84dc99077b9aa50809affc4be6057
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8812 bytes