Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c257c85adfb477a…

MALICIOUS

PDF

93.1 KB Created: 2021-08-07 10:50:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f555a9c1d96d0c5f1a6c01a426df1374 SHA-1: b832acf0d28466c5f5e4d612eef238c67f4d29b3 SHA-256: 4c257c85adfb477a118d54ae4240bd994932254636cf5e94aac6feaa5df3ed8f
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to phishing or malware distribution sites. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://basyapiemlak.com/yukleme_klasoru/userfiles/file/87771555950.pdf In PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/a5aced1a73127ec6b62c2127436252c8/57421294967.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb2742b836---3506884966.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/88332690983.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/wipilosisezunide.pdfIn PDF document text
    • http://memphiscentral1969.com/clients/865565/File/dugomaku.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ea9cfb2be9---12518065331.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c107e1767a3---jusiwoxikovavot.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/584ce6360c47adde409727e3dff21ef7/nefamofidawozo.pdfIn PDF document text
    • http://midlandhigh65.com/clients/6/68/682e31fde28f8c6bff7ebba57332ef5f/File/6465984943.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/jgfn0a2ippk2u2es7m7kvrfh5s/peneligerinimisezamoz.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/1d8aea525a9068c62186c403fb641fc0/sawize.pdfIn PDF document text
    • https://guineaservicesproviders.com/gsp/files/mafag.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/kozunejaxibimejefikukaf.pdfIn PDF document text
    • http://whatdwellswithin.com/file/80027868062.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/76221275759.pdfIn PDF document text
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/javixevabenunejej.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/eussghi692ekph2hbto9ibglk5/25461438533.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1610308c8166bc---fowefanelikosan.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/nozajekasafexibejoluxer.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/40422239571.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d60aa693f3---vosomofadulepopojobu.pdfIn PDF document text
    • https://schlosshotel-murten.ch/userfiles/files/xagurojevevorotep.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/ok5b8mta8i4hn8t6qq8db8q3d3/wuvurujemufetutiwivaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=unblocked+games+24h+happy+wheelsPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/ecc74f5fd16c227890542cf4305e47e6/niwirilojewinomu.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_off0001048b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1048B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9D 18100 bytes
SHA-256: b375e6bbc63864613b07154a8a7088ef496069912cf9c686b6db33bd1ea70c46
font_02_sfnt_off00014c02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C02 11308 bytes
SHA-256: fdf1a39f951b0dce93d0654433bc07fb810ea7887e49f3c6c675be25054a1147