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

Static analysis result for SHA-256 76b34b46338092da…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e74236463825bd0387aebbf5bd6589f2 SHA-1: d09b3420bcc4ee4cbed3e63b7a8a0f625c31c379 SHA-256: 76b34b46338092da810bdca3cd6f97a87ca71466090b286f082eeb4fa382f2c7
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros with an Auto_Open entry, indicating automatic execution upon opening. The macros utilize dangerous functions like RUN and CALL, and construct strings that appear to form commands for executing external code or downloading payloads from the provided URLs. Specifically, the macro attempts to execute code via CALL and RUN functions, and constructs a URL-like string for execution.

Heuristics 6

  • 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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • 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.
  • 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://zerones.biz/ds/261120.gif
    • https://zerones.biz/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
7fbdfe5319125c7a88728c7d99286583a9907fcc6c0161898412d727b081f128
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6676 bytes