Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c4f3bcfb6a4b013…

MALICIOUS

PDF

106.3 KB Created: 2021-08-11 00:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: c7a86e3bdd5496d80f24d1a37d6def48 SHA-1: 53c59e048a57255855c6cef866a4096c7575d8ff SHA-256: 1c4f3bcfb6a4b013255490229da6845ab2205e27924480118d37d4259291aaf9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and multiple external URIs, many of which are part of link farms hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution by redirecting users through these links. The embedded JavaScript is a common technique for executing malicious code or initiating redirects within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://huntic.ru/uplcv?utm_term=tv+tropes+fairly+oddparents+funny PDF link annotation
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/01v8om9m5mtj0draf2a3e79494/jebabelufalojavi.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/gubozokenagisuwikitax.pdfIn PDF document text
    • http://logisticsnetworks.net/ckfinder/userfiles/files/satin.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/14878667813.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/7206476104.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/5ba38f85ba597e2fe89635f3a219d3b2/falutifotowofizeg.pdfIn PDF document text
    • http://elitvorota.ru/f/file/58406185493.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/zenufagubuwa.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aebca99756.pdfIn PDF document text
    • http://beulahcooleycollection.com/clients/870349/File/21196127400.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/9bc7c22f92b72cb8f3b31296abbb7f78/tomaber.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/ud0fidsooc8b6dkoqettqal0t3/36315031350.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1d9e9d4f3---67083539711.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160a6556a39307---webefulazadivilapamawireb.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160abf60a2f7dc---jevaxagifus.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210629005559.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/nexin.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b457a29967f---vawinibosaxidaga.pdfIn PDF document text
    • http://atsrealtyvietnam.com/upload/files/40652710205.pdfIn PDF document text
    • http://yejida.com/userfiles/file/90970698995.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/c7ccd43f92a2cbcd171cfe1febf86893/mivebefeguzoxogimimolagax.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16077b3febe962---newiremukuzi.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/penedimaxurilamokedajogix.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16112eb925b0fc---posef.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_off00013b77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B77 17296 bytes
SHA-256: 335b464670dd807f0bc53915f3d1e817311c41ce645c93f3b2a412e7afb06d58
font_01_sfnt_off000168d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x168D8 10736 bytes
SHA-256: 18d98e134b9cd13bb1f7879743bd9f0dc0ddf3e374cf1449ff697e3239f95c9b
font_02_sfnt_off000181af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x181AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1