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

Static analysis result for SHA-256 c726c2c37b220ab0…

MALICIOUS

Office (OLE) / .XLS

426.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: b3a2c033caaf98f3ff83b4c0e5347351 SHA-1: 5e3fd3f5deedf640a219f75561fc09b9792b6a87 SHA-256: c726c2c37b220ab0dc10791d2ce15265498eed1a32782012a4b7b32bc5ede972
240 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.004 Unix Shell T1204.002 Malicious File T1071.001 Web Protocols T1105 Ingress Tool Transfer

The sample is an Excel file containing both XLM and VBA macros. The presence of Workbook_Open and Auto_Open macros, along with heuristics for ShellExecute and URLDownloadToFile, indicates that the macros are designed to run automatically upon opening. The document body and embedded URLs point to 'https://mueblesmaple.com.mx/19.gif' as a potential download source for a secondary payload. The macro-enable lure further supports the malicious intent.

Heuristics 8

  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • XLM Auto_Open with dangerous formula APIs high 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.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • 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.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • 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://mueblesmaple.com.mx/19.gif�
    • https://mueblesmaple.com.mx/19.gif
    • http://ns.adobe.com/xap/1.0/
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#
    • http://purl.org/dc/elements/1.1/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e26e570691e37538cb153a294d4bd7899ebc79f39ec63fd34cf1eae37efa26f6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 9455 bytes
macros.bas
8c21c322bb8b23e7dbfa4da0de1c41676162b0810e96582d1365413c12adc768
vba-macro oletools.olevba.extract_macros (decoded VBA source) 977 bytes