Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5345809d392431a…

MALICIOUS

PDF

75.7 KB Created: 2021-09-19 11:27:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: de03361cee1a8e86a51497ebfbbd19a2 SHA-1: f73101a1463eb8fa0def7aae7e8db10e71a51445 SHA-256: f5345809d392431a407179c3aa05ff2d4e970c65964ef7b5bcd62eab9e5c8022
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting a phishing or malicious redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing attack leveraging a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://huntic.ru/uplcv?utm_term=3+letter+words+starting+with+g PDF link annotation
    • https://granitnet.hu/editor_up/jugidaf.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/59988237670.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/bagiwaxelebodufumebaf.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/piveruwifimulizedap.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/1567229246.pdfIn PDF document text
    • http://tabletopad.com/images/file/lezapaxexebibibatodunaj.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/39055257817.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/41558231609.pdfIn PDF document text
    • http://thienlongadv.com/upload/files/nupaxibitolojugidilidufa.pdfIn PDF document text
    • http://bighost.vn/uploads/userfiles/file/jelubojaved.pdfIn PDF document text
    • http://apcmagon.com/userfiles/zozowipesem.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/zuxavuno.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/d0246edb94072ed7269d8e2e558a36c0/lubarovevutin.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9ffbd9884---76591535150.pdfIn PDF document text
    • http://iviltra.lt/images/files/xurapoketabo.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/15031233068.pdfIn PDF document text
    • http://surmounttravel.com/userfiles/files/lasivefirezabine.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394135c5be6---pogikofikibufewem.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16145f8dc4223d---75931876403.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/90430441363.pdfIn PDF document text
    • https://maintogelonline2.com/contents/files/4212528830.pdfIn PDF document text
    • https://e-fasteners.eu/media/file/taxuzajokexenetofiruvutif.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_off0000c286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC286 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA9D 10688 bytes
SHA-256: 37a0cfef0bee8443cd59afdb4d9fa90875ae215b42016f94ad5b4a7b615fd9ad
font_02_sfnt_off0000f2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E3 17812 bytes
SHA-256: 6876ec51e92f5886ddd0405b4993733b6be907b2f8935b482a9b46330c3458a4