Malicious PDF — malware analysis report

Static analysis result for SHA-256 73ab5be2c23b1791…

MALICIOUS

PDF

71.4 KB Created: 2021-09-01 07:26:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8ee5086c41d5b1b8df36fb3df8197008 SHA-1: 7b4b920eb4116e982f65e780a249d62a86c65da4 SHA-256: 73ab5be2c23b1791f83755e5013a6e0fd8f69f4114704421277526db27e24acc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by ClamAV as a phishing trojan and by an ML classifier. It contains a large number of external links, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://aqs-group.it/userfiles/files/76323006898.pdf In PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be6b14c7de1---84572968715.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/32022601729.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/54736746945.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/mdtd6ghvtjtgveov19viej33v0/ligevepizufewabuv.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/72727627420.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/27201kdd9cfkaj066nf5ri9480/72575223115.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/83702870741.pdfIn PDF document text
    • https://ancoraeducacion.com/images/61474814632.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/8789762013.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b410357abfa---dumusafimi.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/2b372b4cd316449df95dc57492dea797/jatekezufarasavebu.pdfIn PDF document text
    • http://techbico.vn/uploads/image/files/gajozazufazikizuf.pdfIn PDF document text
    • https://eurouniversal.eu/ckfinder/userfiles/files/35529204142.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/files/gimaf.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/jivosejejenosereko.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/tn4hfnikakrrrhog2d3k2iepo4/fuzabeva.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d95cb62803---5361244729.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/9932faf99882fa85ff17c57bb58bf0d7/gixozoxifat.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610440a16021c---48259150605.pdfIn PDF document text
    • http://bjaimama.com/data/upload/2021/06/file/202106171305224607.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/3097e84973fca8c4328034fd1195d55d/dezofemaze.pdfIn PDF document text
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/684pc9c725kmutkd1vbmu1j1rl/5585293589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=engineering+an+empire+rome+viewing+guidePDF 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_off0000b8dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8DD 14860 bytes
SHA-256: efb476fa950c09a128e2d1cfa9f6a94e1c989baa6e8949f447a6a2d121a8766e
font_01_sfnt_off0000de6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6B 10660 bytes
SHA-256: 270575843e4f8cf79d5c8057376f17d6365b28c15689fb5e31d835ab3b9ee070
font_02_sfnt_off0000f694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF694 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1