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

Static analysis result for SHA-256 1831918f2843b877…

MALICIOUS

Office (OLE) / .XLS

380.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: a8f34f2a8de7b470c474c50c8cd4b15f SHA-1: 70b5c1b33f8e3229d9bf5e1d05b3d480b43d7147 SHA-256: 1831918f2843b8776185be0dce38810c96476e052cc88509b801a4a3a9f3417f
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, specifically an Auto_Open macro, which is a known technique for executing malicious code upon opening. The document body contains a lure to enable macros, and the extracted URLs suggest a download location for a second-stage payload. The macro appears to use 'rundll32.exe' or 'regsvr32.exe' to execute the downloaded file.

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://hermescomm.net/x9NvrhL0/lena.html
    • https://asistenciajuridicaintegral.com/6YiCkNix5/lena.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
be629cb484f8d82e38c4234ddbad4f1755e762b9c1c8359642d99f8c77e6e858
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8812 bytes