Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4aea21fb2eca717…

MALICIOUS

PDF

72.4 KB Created: 2021-08-31 04:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 983d0536f47b6a53f907b7a272d558ae SHA-1: 3f722a4941411d3e3f0ab7921fdf0791fa0155d2 SHA-256: b4aea21fb2eca7172ecb85376ef97cef32d997e7fdf02add58a5d34030a77f99
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://krisoc.ru/uplcv?utm_term=average+speed+formula+when+speed+is+given PDF link annotation
    • https://tahitotfalu.hu/ckfinder/userfiles/files/naxexizipatelak.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/803122af26e939bd0ea25447ffc24fdd/poreludavisexepukasaku.pdfIn PDF document text
    • http://poorclarescork.ie/images/baladowaxada.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/a7cce1d049a26b7878661ef5413f71b3/xefakita.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021082504501653.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fab602be35---bilejagafinisow.pdfIn PDF document text
    • http://bizbecho.com/pa/trainstation/uploads/image/file/78705620860.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/faxogenefatumor.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/hoqu2tskf337ih418v9l9m8ot1/mefimokise.pdfIn PDF document text
    • http://contelex.it/userfiles/files/18522153314.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160991fedac4b2---79873866306.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/wevubezejos.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/zajezajolukoparogilazuge.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/lubulazaxelegosida.pdfIn PDF document text
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/824f9382dcfabcebf834aabeb7ab1787/11205541377.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/16037174797.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1bc8ba20e1---73770864074.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/gixuragajo.pdfIn PDF document text
    • http://sierrahighalumni.com/clients/878712/File/kapufizadedemev.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/lifow.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3b4d5bd6b---42539422021.pdfIn PDF document text
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/75538029257.pdfIn PDF document text
    • https://www.colline-eternelle.com/ckfinder/userfiles/files/winumixemivu.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/51954125668.pdfIn PDF document text
    • http://studiozammuner.eu/userfiles/files/setotifikus.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd21e4cf9df---silolurudexizuliwada.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_off0000baf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAF6 11080 bytes
SHA-256: 7b8b4fcce49505c8f1e7b478d299d820db804e7f033b7efde6eb594963ecb3a9
font_01_sfnt_off0000d465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD465 15224 bytes
SHA-256: b7a9afb602a52e0e38b833cbba395ff6924766878bd9fe8bdd5eebbfcac417df
font_02_sfnt_off0000fad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1