Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a197249f9c4bf5e…

MALICIOUS

PDF

33.5 KB Created: 2020-06-03 09:18:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-07
MD5: a1c465f3a390164cdd6a181ade05ba65 SHA-1: 56580ff03f09b231811fb94443ca0059e655a549 SHA-256: 4a197249f9c4bf5eb61adfcdf691d7d2481d1a1e43f4fe51406b92846909e5f4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of external links, many pointing to SEO-optimized PDF files on various domains. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass external link farm, and the ML classifier strongly flagged this PDF as malicious. The embedded URLs suggest a redirection or content delivery mechanism designed to exploit search engine optimization techniques to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 http://stayusahotel-wb.devsite-1.com/uploads/1/3/0/4/130489131/130489131.html#tipos+de+palabras+por+su+morfologia PDF link annotation
    • http://webdisk.valleybookstore.com/uploads/1/3/0/5/130589252/xodogefona-bimufe-wudokivag.pdfIn PDF document text
    • http://sanctuaryhealing.net/uploads/1/3/1/3/131384656/jurarekakok_xojejepukov.pdfIn PDF document text
    • http://granvillebates.com/uploads/1/3/1/0/131070089/javufokenite.pdfIn PDF document text
    • http://stayusahotel-wb.devsite-1.com/uploads/1/3/0/4/130489131/terms.htmlIn PDF document text
    • http://stayusahotel-wb.devsite-1.com/uploads/1/3/0/4/130489131/dmca.htmlIn PDF document text
    • http://stayusahotel-wb.devsite-1.com/uploads/1/3/0/4/130489131/policy.htmlIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://furolizi.files.wordpress.com/2020/06/92098196159.pdfIn PDF document text
    • https://nujivilij.files.wordpress.com/2020/06/24693675381.pdfIn PDF document text
    • https://piwojuduxuf829276773.files.wordpress.com/2020/06/11461921017.pdfIn PDF document text
    • https://kipevofi.files.wordpress.com/2020/05/mawiki.pdfIn PDF document text
    • https://vemupuki.files.wordpress.com/2020/05/55254565432.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005625.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5625 10756 bytes
SHA-256: 9dd4ebbb3655895ded6f176ca44bfae4383f9e5abca74287a5ce79983dd05c6e