Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4dfc57cd38cf444…

MALICIOUS

PDF

97.0 KB Created: 2021-08-07 14:44:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 5472652e96e597710d99cf7a3b1d13a7 SHA-1: 30c9c98725e5e22b2ccb4910f513d439c4d7975f SHA-256: a4dfc57cd38cf44464c759e292ec99be684d02e11feb6f1020d5083d5f4aaa6e
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The file's structure and URL patterns are consistent with a malicious PDF used as a lure, potentially for spearphishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/f01a00865d1bade7987946116ece534c/vuxiziderexu.pdf In PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/b32e47d7a4d7696d975d1a5fbb88d74a/sixetekodenogifu.pdfIn PDF document text
    • http://medical-1669.com/userfiles/files/jipeno.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077bb3163a63---dimuxujubevolir.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0145eb3e08---14488624513.pdfIn PDF document text
    • http://tutaylamhet.com/storage/ckfinder/files/zaradini.pdfIn PDF document text
    • http://protok.pro/upload/files/viridijezowogabalep.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/32a3fe46cf6675db0e7aa44d65f99382/79855531954.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/12818317828.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/kopowesefalonibik.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/dovitebexiwaxad.pdfIn PDF document text
    • https://krossi.ru/images/content/files/pelujemugapubexa.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/wuzoxugiguradidu.pdfIn PDF document text
    • https://wulf-sanitaer.de/wp-content/plugins/super-forms/uploads/php/files/its2oehk2nc953d1etilr4udpr/tutagowexufi.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/a49e055d3b4ca0dfab56fa0988ad6664/zosadofixipadozirek.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/56477950356.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/90871933576.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c899e1b37ab---73099201549.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c85c2b53ba0---49957006199.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/lerajovifibikexozupera.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/08b324073355417693ea752a491fb602/51155139070.pdfIn PDF document text
    • https://mytekas.com/UserFiles/file/49144646989.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/abdbd5e4a471e1a4d1bc33e0cdb34533/jovupusax.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/fonusaxajetugid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=codigo+de+processo+civil+comentado+nelson+nery+junior+pdf+downloadPDF 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_off00010c21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12433 21336 bytes
SHA-256: 0df7042abafb3efb03fc641843c2498ace4d299182fd1f6bf52c1476d664fc86
font_02_sfnt_off000157c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157C0 11488 bytes
SHA-256: 9f432877fbedf5d46167db456f63d784e1f5ff04bafba414293435d4d01feeed