Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d849fc36cc12cd0…

MALICIOUS

PDF

74.7 KB Created: 2021-06-29 09:30:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 07a32237f16658645a04ba17752dffe9 SHA-1: 05afebb2d260c8182d8ac83f3c2b260e79d00d55 SHA-256: 8d849fc36cc12cd0453ff5c2e57eccac2a851066df76810ee80c8f2c072282a7
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm designed to direct users to external, potentially malicious, content. No scripts were extracted, but the primary attack pattern involves luring users through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://medvor.ru/uplcv?utm_term=what+is+rhodium+silver PDF link annotation
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/7b29fe5e95484d5a22b464574467d78a/18941305632.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609891db22f03---vuvavaxobexekunu.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/xawubuf.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/64365719542.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/30669562152.pdfIn PDF document text
    • http://maristaslardero.es/userfiles/file/gagunesodaj.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/15rhkguj36416kvkeiodntjnq6/mogunoraranesifared.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/watugajog.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/581055a7854fc0a2830d5b28ee87cb96/52929510071.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202104/file/topomobofexeno.pdfIn PDF document text
    • http://yesilderecine.com/admin/editor_resim/file/40459744931.pdfIn PDF document text
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/68840745478f97786912bbf2bf8fde9a/45721766674.pdfIn PDF document text
    • http://mebco.ru/images/file/98540710505.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f76cce07c---fulavakixolulobo.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607579d975576---95768019393.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c3f7555f8---lakewali.pdfIn PDF document text
    • http://better-pharma.com/images/file/files/pazizufojuk.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/36255444099.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/d75957c73887423f26b661d056cc8326/zodososevilixalifetexiv.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/49358835123.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/9319602e7c6d0d6bdae7422148f215cc/nadaruxibolilaje.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607765f6e97df---zimuvexegamofawij.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16073cda235f7f---jasufisapil.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/871cbf644cdb895f57d1115d57102907/80063494640.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/3fiheoh6e9816r4pg3suak4jj7/6970672001.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC594 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dda6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA6 15448 bytes
SHA-256: fd9f386389168d68fc1605ed2deadde1cdc22d16dda936a15f27804eab606586
font_02_sfnt_off0001055e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1055E 10568 bytes
SHA-256: 6cf27550aa8d67ba9a2362c0318ed1ab179178bb7572f08da7077f722968b5fb