Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf3ecca9c1369228…

MALICIOUS

PDF

72.7 KB Created: 2021-09-13 14:43:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9a014f79bad7baad5ebf62cda3ad8fdc SHA-1: cb88ba832cfdbea8cc220242aba8bdf1f766e2a2 SHA-256: cf3ecca9c1369228a7c5f986241e5d8158a6dc2f08e011433c65e87493111094
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of compromised CMS upload links and disposable hosting further supports a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://cathugo.de/res/wysiwyg/file/rutaxaruwewa.pdf In PDF document text
    • http://guchen.ru/d/files/33032190027.pdfIn PDF document text
    • http://sparkpro.lv/content/file/gesagatanejim.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/59041458583.pdfIn PDF document text
    • https://nk-sostanj.si/files/file/morironenaz.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/ab9dda75b1dd8e286b16d0daa1aad46f/2933907916.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/75585796551.pdfIn PDF document text
    • http://carlaschroyen.com/content_docs/nenemagudusawesu.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/13720108247.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/10415776303.pdfIn PDF document text
    • http://cgpreceptor.com/ckfinder/userfiles/files/lasad.pdfIn PDF document text
    • https://neurondevelopment.org/userfiles/file/bebutabafefanumixesuva.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8116edddc---62986887118.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/wimarorirojugonaxokatisu.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/12785730212.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/3801678620.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/a2mou8bvn6j3mh7j4qdprngg22/60031504679.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/gozasopalesidusiram.pdfIn PDF document text
    • http://simsvizag.com/admin/uploadedfiles/file///sidujolu.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/jinawupitibin.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db8a4e1a33.pdfIn PDF document text
    • http://frickcontrols.com/uploads/files/zirisivoxozoxifotafu.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/518029684.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613608eeda58e---60629525945.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/90092197681.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=doodle+art+app+for+androidPDF link annotation
    • 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_off0000bbaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBAA 16284 bytes
SHA-256: 1d46faec1b4966f8182788f104fee8771ab60234b97a938c324d409f165823db
font_01_sfnt_off0000e5cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5CC 10324 bytes
SHA-256: 65c6281997a76091d164bf44a192a4bef346e6a4ad74dda4eafeb57025011577
font_02_sfnt_off0000fd1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1