Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81238fb4b828951…

MALICIOUS

PDF

80.3 KB Created: 2021-06-07 23:07:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ed5e83d6dfd287791d8205f8700940ea SHA-1: 6e0236a2908ad2726c8be9ba08853fd6df9144b6 SHA-256: a81238fb4b828951aeffca2ef244d8f77e98cf9279515059b5678353062243c6
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and is identified as a link farm hosted on compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://allytemp.ru/uplcv?utm_term=ejercicios+sintagma+adjetival+2+eso+pdf
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608836dedfd00---46683628608.pdf
    • https://plasy.com/uploads/file/22593082113.pdf
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/85vt279ep0t4arli78m5hnn4o0/34543353473.pdf
    • https://psychologgia.pl/Upload/file/fuvugopetuvepilupe.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607829cbaedc9---60048978987.pdf
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/b840fb05f627e587108160a2366d9913/rebigimixibumidagagoz.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072c819ae734---perusewewagagezimekemimor.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/jo7a749qhaon69gfplbnb6vpa3/52753179360.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608742dcf0d12---92545842291.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/fb8e5fa2b538a10303bea8f1609dddcd/564929767.pdf
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/d6e92287ae57903e65589a8fa696dfef/fimodimapirawisuf.pdf
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/d4f3be2f71f09e5983bdb0ea7194080a/74256979051.pdf
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607c430141d3e---mitizedev.pdf
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/84a872d20973aee50f67844931b35253/nopubivafiwufifuxiwifol.pdf
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/d9a7968f3107061044ccb8a3df94e21b/sumofi.pdf
    • https://autotronics.vn/userfiles/file/34456566499.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/i3ur2kfacu1f0ug34hhiv7rtvq/bobamofujifutugut.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160784fd6e3858---vekokurorag.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e57f.bin
2db94ef9a17d399c800d98850644ce9585ce60dd271e2e9fff619de0c51fe38a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE57F 5700 bytes
font_01_sfnt_off0000f8e6.bin
0056e2762b22a7511877bd802131dd05f8e56d2d42eafae818523afd4ef6e8b1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E6 11784 bytes
font_02_sfnt_off00011eeb.bin
62057359ad22ed6c79ab6a94c34af50e7f9192dd49eed379a27769cab1f8071c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEB 16064 bytes