Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4f6bb352f6aa35…

MALICIOUS

PDF

72.4 KB Created: 2021-09-04 22:19:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 74a733d7c3a46a04a7b8f5a4a721580c SHA-1: fbc35f935e6d29d07b260a46c918e32fb4195e17 SHA-256: 8c4f6bb352f6aa35416699496cf271b3946cb2d99ab6d165d34138188ad0ca4b
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://cructi.ru/uplcv?utm_term=subaru+brz+manual+for+sale+philippines PDF link annotation
    • http://nhasachconggiao.com/luutru/files/80926379531.pdfIn PDF document text
    • https://rdsdealers.com/ckfinder/userfiles/files/depolara.pdfIn PDF document text
    • http://zimaletto.com/uploads/file/zamodorif.pdfIn PDF document text
    • http://wenxuezj.com/images/File/6464389804.pdfIn PDF document text
    • http://moriefrusca.com/userfiles/files/pakutemuni.pdfIn PDF document text
    • http://worldwidefilipinoalliance.com/uploadedFiles/files/74816060313.pdfIn PDF document text
    • http://americasbestwingsbeltsville.com/uploads/files/lupegofozezasudukoxenin.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/tabax.pdfIn PDF document text
    • http://denprokhorov.ru/images/file/talowozifoba.pdfIn PDF document text
    • https://tidurmalam.com/contents/files/kovegavojovaxam.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160ad98111822d---63873853810.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/f2c7a21de11fbe9cf6fc29adc1ab98e3/lanuzekuwasa.pdfIn PDF document text
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/ghgmnht2b2qrauh5h04ie32cl6/19534848633.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/7658333e68589925f10244c374192a32/juniwikarudup.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7549311e0---79699323785.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d7aa1cc61---75273367694.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/6081104072.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/14383110371.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/19375811951.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/bikaxazazulogazixatipeki.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c87e1aaf285---pefivub.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_off0000b960.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB960 16536 bytes
SHA-256: b44f3a2a5c2fd167fde4130904e3a4f8b332e926ec7fb2fd36321ca239d38800
font_01_sfnt_off0000e39a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE39A 10900 bytes
SHA-256: 22e11e7709b1ac07250a279c22b421fdb7c759dd978ea6189544b014bad652d2
font_02_sfnt_off0000fc5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1