Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e8f68405fafa02…

MALICIOUS

PDF

75.0 KB Created: 2021-08-12 08:13:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: f866a8c23bce9ac62e2ce6114822ff95 SHA-1: ee9f8c62a4ff6a587ee1b8818e58e569b9ea5f94 SHA-256: 81e8f68405fafa02c95d908c46dd4907a39b6c391341f9235a6d57e4cf1bc416
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, indicate a link farm designed to redirect users to malicious sites. The primary attack pattern observed is the use of a PDF as a lure to distribute phishing content or further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://archism.ru/uplcv?utm_term=glencoe+algebra+1+textbook+pdf+2018 PDF link annotation
    • http://eko-inwest.eu/upload/file/30156189535.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/zorekiwixipufe.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/66378074902.pdfIn PDF document text
    • http://quatanggiabao.com/images/uploads/files/tapufigewiwejadanexadof.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/91a1718fdf648c7359cfc7dec315e1d4/bejuserilevob.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b5dc8c9c2ab---vezamuvagedigisodi.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/56297546988.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/0fd5c860e8abeb7c0a0c8d9e6e602458/rovurowukaju.pdfIn PDF document text
    • http://www.asslar.de/downloads/57839130452.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/a6bad70ab886bdd2925d63281d12ad7b/towawozaviregitemepebako.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/pidopovujimam.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/99210967753.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5b293b626f---vufunagipitorofirasagug.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/97595007791.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a5cfe35ee---gadaxijurezidu.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/0a9681894fdb5d9f5aede9eb9fa902e3/4134511394.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/notopusofobefemokopixud.pdfIn PDF document text
    • http://vncdata.net/app/webroot/uploads/files/kunuzajulanora.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/dnttl47b9nofk1kp774lb40sa6/derakum.pdfIn PDF document text
    • https://dehayemek.net/upload/ckfinder/files/46920040062.pdfIn PDF document text
    • http://sarljarry.fr/userfiles/file/wikitutokuwekosaz.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/depotaleropu.pdfIn PDF document text
    • http://vuoncotichdep.com/upload/files/xaposajuki.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/zibosuririsusovemefawa.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2af963cf7---80252033528.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_off0000bfda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFDA 16664 bytes
SHA-256: 6e850a26402c400b823b02963a1c39cba56baf99582f8c251f6f175b3565cc31
font_01_sfnt_off0000eb9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9E 11412 bytes
SHA-256: 4673a3c377c212e24d746d7c1f659a91ca9225f35b1d6cc812d10f4e4299cc1b
font_02_sfnt_off00010663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10663 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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