Malicious PDF — malware analysis report

Static analysis result for SHA-256 1251f9fa43200281…

MALICIOUS

PDF

88.3 KB Created: 2021-08-13 03:44:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 476f23cca7b67fb976476df951acf52a SHA-1: 90a27d5a610a9e4ca262b86766ac19a6bd00e24f SHA-256: 1251f9fa432002815df9d3ee42f55713a576567d6e2725bade05cd43fa4800f7
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, suggesting a phishing or malware distribution scheme. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, as these rules flag PDFs designed to leverage external sites for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://crysiq.ru/uplcv?utm_term=2nd+grade+phonics+worksheets+pdf PDF link annotation
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/fuqhv2qg65hm2qg4qrd7h22tut/kewenoxopez.pdfIn PDF document text
    • https://groupunsur1.com/contents//files/90041057325.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160734f06532fc---kegoxefugesilimi.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0603/df3583111c81381443df886d1d92d921.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16096774004368---jejokofegadelutuvekos.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/laxuderesatilaredapo.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a35fe4c4a31---tulosubawevajizasowu.pdfIn PDF document text
    • http://cuatudongbinhduong.net/uploads/files/9053110027.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/samipidejebili.pdfIn PDF document text
    • http://rivieahk.com/clients/5/51/51325344bd1517f257d6959d5350918e/File/magug.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/6def612b06915c2b730595c8194f8b01/57417550645.pdfIn PDF document text
    • http://greenberetrotcmedals.org/clients/e/ee/eef2f5edcbf7b69ea683240098563b39/File/48938167170.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd6cfcf985---pezabobabin.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/f3ek6chpqtemllri4svpaftnf3/56161274278.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/nusitezazojefokaditog.pdfIn PDF document text
    • http://4bx.pl/public/file/98947348941.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/82dc9ed07856ac1c4c4813a6ba3de64b/90735845204.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/a9md44ug4s2lah9s60ifg42hl2/33234911449.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/47340573257.pdfIn PDF document text
    • https://www.myosiaffiliate.com/199trust/img/file/87145265692.pdfIn PDF document text
    • http://richmediahouse.com/admin/uploads/file/diwuwujegigemur.pdfIn PDF document text
    • http://dailygiasi.com/uploads/userfiles/file/50177517923.pdfIn PDF document text
    • http://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/0e3162507c23845dcbb0d1742db44cae/87968251553.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/bec7c49c0290b4826179548983b256ac/redugekesedawafivutibeden.pdfIn PDF document text
    • https://fanaf.comarticle_ressources/file/bepezopinewuzudaliwubo.pdfIn PDF document text
    • http://textingrights.com/userfiles/files/55362795168.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_off0000f3a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A3 17272 bytes
SHA-256: 0cb32fdadee4edf31ab4ae119e7f1d859f37ba88061b73ac3e936f48e244969e
font_01_sfnt_off000120d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000138eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138EB 11052 bytes
SHA-256: 6d68e40db84c5e1ed26bd0b1cb365233bf9ecda3371b817e20c2261580d7f7e4

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