Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcffbf1d899cbcf8…

MALICIOUS

PDF

79.6 KB Created: 2021-09-10 09:47:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a22038664d608ec1fa6d8e0902b0322a SHA-1: 30b18e3da8c4ab12ad5b6e9a06aee0d8324b72c6 SHA-256: dcffbf1d899cbcf8517cd21728589c9cfeb9c5850cfcdefd272ca0f87692b26e
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with multiple URLs pointing to compromised WordPress upload directories. These links likely serve as redirects to malicious or phishing content, aiming to deceive the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613992357a48e---98687606556.pdf In PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/50201764982.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/53732894466.pdfIn PDF document text
    • http://mlsy.cz/images/file/files/vitonilebilosi.pdfIn PDF document text
    • http://naosgym.com/userfiles/files/gugulomijefowoxetuzulofe.pdfIn PDF document text
    • https://hantverksakuten.se/ckfinder/userfiles/files/32316090394.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/tobaturakupo.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/7992826294.pdfIn PDF document text
    • https://panificioilcavaliere.it/userfiles/files/vifediropajavenekisuw.pdfIn PDF document text
    • http://lncxjzxxw.com/upload_fck/file/2021-9-6/20210906160152875375.pdfIn PDF document text
    • http://www.hausman.eu/images/wyswig_images/file/genuku.pdfIn PDF document text
    • http://ekachaiguitarist.com/ckfinder/userfiles/files/65729742162.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a169907b53---zidupevivig.pdfIn PDF document text
    • http://gesgo.de/userfiles/file/16683958471.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/14929971208.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/30ef4e73ba71a03491ef1e28fa08f013/45623201512.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/pununawif.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/96538219342.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7ff246217---jefozorajev.pdfIn PDF document text
    • http://01host.ru/userfiles/files/32114878719.pdfIn PDF document text
    • https://cncunse.com/d/files/jobabi.pdfIn PDF document text
    • http://saatgaamkansarasamaj.com/admin/uploads/files/69482143811.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+turn+off+cookies+in+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_off0000d258.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD258 17416 bytes
SHA-256: ba0d483cc75b25ba2e66f64b342ce355f62b71be13314012f557cd1f0e554660
font_01_sfnt_off0000ffce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E5 10692 bytes
SHA-256: d02f9b592478e3aa456a315ae7247d590e1a2dada8198a6064bf71c0bee315d8