Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dc8e4889f480ab6…

MALICIOUS

PDF

79.5 KB Created: 2021-06-26 16:33:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f8d178e2f3cfd5094f691b8a9eff50a2 SHA-1: 14283f3cd1b142135bf8dcd17e7108c38f5b270b SHA-256: 3dc8e4889f480ab6a144695e5505df6f5b8bb25b90e6ccb844c4eb28c2c5cc8e
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised WordPress sites and algorithmically generated URLs, indicating a link farm designed to redirect users. ClamAV and ML classifiers flagged this file as malicious, specifically as a phishing trojan. While no scripts were explicitly extracted, the nature of the embedded links suggests an attempt to deliver a malicious payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160808c604a88d---lomikuzezagejowexerosuju.pdf In PDF document text
    • https://aimara-bg.com/userfiles/file/88801998724.pdfIn PDF document text
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/h564dg414aqtijkq8sj5vr54pa/nifezopelaxatetalukemarut.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a17647b1288---98719111125.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/e6e7964e078e3d0961a546baee3b1248/soranupufuwog.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/78584933959.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/fijjf9d6il1sfn74pavh32s8p3/juxilogizidolitijufe.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/f66c137b9071115ccf204c694601fcd4/91384275128.pdfIn PDF document text
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/a8fb0f6b4bc847b9f725dacbeb392278/miwalixakisiju.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078ce575db0b---mosajukumepuza.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/6551527736.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/is2lqsve71uvf46i66erc07h42/guzuxelupujekekune.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a3ac9cbb5518072540c1cb2735efc053/32431769330.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609edb09d86d6---75099234753.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcdfb22343---komivemenusosu.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aad7fb44e6c---70550512400.pdfIn PDF document text
    • http://dogoxuavanay.vn/uploads/files/gemenugemapuvibuzav.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16098e551e17b6---bobokibiwilinazazupuza.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/h6v15u5bvhlffam4pcq0ie1asq/jesuvuresujakaxubedizazu.pdfIn PDF document text
    • http://thecreditcrisis.net/clients/73966/File/87382905395.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/a27fc9de5264f242e633da88edeceb5b/kuwuxafuxivilofuz.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cff0a253c01---nizexofok.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/dexotelu.pdfIn PDF document text
    • http://maduraigarlandshop.com/userfiles/file/79566118556.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/sivazowajujabixutomesap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=pink+lady+apple+nutrition+informationPDF 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_off0000d311.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD311 16972 bytes
SHA-256: 916e3809d8088f6b6234cde1554783ee613b08a5d53abf8809cf9d615e1a5a44
font_01_sfnt_off0000ff95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117AC 10800 bytes
SHA-256: 5543299706ccf6dc87098316d81ff2c7786f5ee9efd02fb1868e13401fbed9de