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

Static analysis result for SHA-256 6a99c5e1d799cb11…

MALICIOUS

Office (OLE) / .XLS

380.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: cdef1c2d5e642c06b886800416e6b6ab SHA-1: 6b97a4fa34c5ed02bce4521c64a0ce909b37c67f SHA-256: 6a99c5e1d799cb119f17a38786d7a4089ed5fc33827c126d346a2af8f5c3801c
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 4.0 (XLM) macro-enabled spreadsheet that uses an Auto_Open defined name to execute malicious code. It contains a lure to enable macros and embeds two URLs that are likely used to download a second-stage payload. The script also attempts to establish persistence by writing to the Run key: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\Server.

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