Malicious PDF — malware analysis report

Static analysis result for SHA-256 51751a1130389ca8…

MALICIOUS

PDF

71.7 KB Created: 2021-09-19 22:08:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cec2187f67767c6af17c00d5e7221171 SHA-1: 45e357af4a6bc15f153db9553ea0fa03a1673b81 SHA-256: 51751a1130389ca8b78de5202d6ffb17dd8fd7149cbf9ebab8c550beea1d114f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2b5d0ee39---2562906735.pdf In PDF document text
    • http://theponghop.com/upload/files/giginokusobu.pdfIn PDF document text
    • https://ismart99.net/upload/files/98041740671.pdfIn PDF document text
    • https://www.truck-transport.com/ckfinder/userfiles/files/tuwubam.pdfIn PDF document text
    • http://titusauto.hu/kepek/file/39410814018.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/62982764635.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370de30651f---28458139761.pdfIn PDF document text
    • http://svenskafik.se/uploads/fckeditor/file/23693384096.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/xolopi.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/68835522840.pdfIn PDF document text
    • http://skncn.com/u/files/83695167919.pdfIn PDF document text
    • https://loyallcanada.ca/editor_files/file/6471859316.pdfIn PDF document text
    • https://sapporopools.com/contents/files/82921120673.pdfIn PDF document text
    • https://mlspoland.co/files/file/57378123363.pdfIn PDF document text
    • http://chaitraglaze.com/uploads/90837472956.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/26112179415.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/73947701473.pdfIn PDF document text
    • http://htwy.com/upload/file/rakimufo.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/25431267345.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/kewusisolulinaginebekevu.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613192ac4a746---libafiwazoxozizofifad.pdfIn PDF document text
    • https://infosantiere.ro/userfiles/file/jagoj.pdfIn PDF document text
    • http://terredellamagnagrecia.com/userfiles/files/6597150695.pdfIn PDF document text
    • http://praguetransfer.com/files/file/geveponanuzimowakajig.pdfIn PDF document text
    • http://chipgene.com/image/files/20210909_071447.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=apex+live+wallpaperPDF link annotation
    • 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_off0000b78b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB78B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFA1 9992 bytes
SHA-256: ea2749563f22c4fedf41291afad54a73560be08ef1ed07d753a8ac3f1ff152f3
font_02_sfnt_off0000e5e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E8 16684 bytes
SHA-256: 9a548df7b860c26d6baa098d26b12149edba6e975f12e5dc4b545db20c29040b