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

Static analysis result for SHA-256 88d81f77fa6040a1…

MALICIOUS

Office (OLE) / .XLS

380.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 91eb4aec7e3e8188f7344d89dacbaa87 SHA-1: a155df4effa352f46fe4068ac20cfb29adab930f SHA-256: 88d81f77fa6040a1c22510f796faabfc7b711b05060d805283b9669b8241cf55
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample is an Excel 4.0 macro-enabled workbook containing an Auto_Open macro, which is a common technique for executing malicious code upon opening. It uses an 'enable content' lure to bypass security settings and instructs the user to enable macros. The macro sheet contains embedded URLs that are likely used to download and execute a second-stage payload, as indicated by the presence of strings like 'downloadFile' and 'runDLL'.

Heuristics 5

  • XLM Auto_Open workbook with payload URL or enable-content lure critical OLE_XLM_AUTOOPEN_PAYLOAD_LURE
    Workbook contains an Excel 4.0 macro sheet with Auto_Open / Auto_Close and also exposes a payload URL or enable-content lure in the OLE bytes. This combination is a high-confidence XLM downloader/social-engineering pattern even when formula recovery cannot decode the full macro chain.
  • 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