Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c53fa388fca2a10…

MALICIOUS

PDF

78.5 KB Created: 2021-06-26 06:44:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c091ed5d503fe65cc43d9d31ccdce19 SHA-1: a212107140cfa1c99512ef65166261ae097543f6 SHA-256: 9c53fa388fca2a1040c8707203c697fd243d08450037bec1d6d8639e06b78e42
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to host or distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/e7kmu3o258tn0blbu4lb94o7dn/pebox.pdf
    • http://wrhs1967.org/clients/6/61/617565fc8afb9cc6d18abf932d248b7a/File/18430417336.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160c5a3e0a091b---40780367536.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099de058df69---98738740614.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f53b903118---70335193061.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/bic868p2h7rlopu1rinstct7pm/98160840949.pdf
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/9eb368f317c804bb282cddaebf503bd2/velebowinonakifo.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c683b961210---texadiv.pdf
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/rekubu.pdf
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/ff2c318e6dba1d2fb9af8cf6afc10668/33918152395.pdf
    • https://jordan.si/dokumenti/file/2944565647.pdf
    • http://thedewakohchang.com/image/upload/File/utigonuzez.pdf
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/ee43cbc1759cc33d01d707023e4634df/wunegemilofunafumoz.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607612d509ce8---dujovuvulofoborewoxixije.pdf
    • http://boxerdapolenta.com/cmsimple/images/file/nidesojetivuz.pdf
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3365bed6d---takagisowuboz.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/5e2d882f8a1a37c7276f6aa1bb26638d/17057947722.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/44fb0d2490b9d265fb3a26a5b2d8d008/vuguwona.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/4rmrui2f4flujli41ao37qr1o6/5366750700.pdf
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/59ede81525a3b5540e9bc6c445308b66/vepiditufupo.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160939edbc9f02---gewasowadizimos.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a4e453d56---pamizurunus.pdf
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/afb1667f8bd1678136e3167a60c77c27/joripozavotijop.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16093f6953a5dc---66341415209.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/08e8be19e2fa684a5a6e10097eaa22ee/xupetozuvixowadoroja.pdf
    • http://washchienluoc.com/upload/file/jiwadilowazitux.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=tyler+lady+may
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1c1.bin
6181f59169b36bfa04f8a1f6e581c7ae6c360383792b855b2d6be1a4b3432816
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1C1 16656 bytes
font_01_sfnt_off0000fd53.bin
dd3f6ff8f52d1f3ccc376aa12213b8f9c1a7b871918914ffb333aeac25254b59
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD53 9904 bytes
font_02_sfnt_off0001132d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1132D 16792 bytes