Malicious PDF — malware analysis report

Static analysis result for SHA-256 135a9d416984046f…

MALICIOUS

PDF

86.5 KB Created: 2021-06-27 03:56:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 81e14317836c6d89f23d0aa6d4c084f9 SHA-1: d551f1baccd76124394fb78fe747c1a01f992a74 SHA-256: 135a9d416984046f861f4aa36c978b13d113cebee9dc34b20b97fc3b1584056c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. Heuristics indicate this is a link farm designed to leverage compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1608526570185b---kevorijako.pdf In PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e8de5c466---mirawedafabibibadexode.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bd740683a---50051099246.pdfIn PDF document text
    • https://hiampelectric.com/wp-content/plugins/super-forms/uploads/php/files/0e1c01738c7a4d59916afdf3dda87396/61727976448.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/vevewilabeveleni.pdfIn PDF document text
    • http://health-bridge.in/upload/file/befisigurididi.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609e8e9bebac1---77977155455.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/43b850ac2b2f61e39ba4d4ccbc495b68/gegev.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160a0a88e255f3---81258585535.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079bfc6ca562---23654337750.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c3a690081b7---41972425286.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/lipkfhjkrn3s2fkthgdhi0qph4/meposigumalelidepefaga.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a15cf42dae1---jatizex.pdfIn PDF document text
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/98215246e2505f3caa487a9bf9769998/19730866292.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/fefinuvasofodogufataxa.pdfIn PDF document text
    • http://czytamzezrozumieniem.pl/userfiles/file/34151640926.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae9a815831---93248572046.pdfIn PDF document text
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/pimeioqt815kfruc598pkb97hd/vexivowefivug.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/menajuruwomaf.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/86065668842.pdfIn PDF document text
    • http://lacasedescaraibes.fr/file/38395711230.pdfIn PDF document text
    • http://dominopark.pl/public/upload/ckfinder//userfiles/files/36848180975.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/jizufebez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=can+steering+rack+cause+vibrationPDF 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_off0000ede4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE4 10788 bytes
SHA-256: cd56733f5bdce3f4c9250d5e4de0f5df7c7f6e968181a62e4d96e9745ef0bd1f
font_01_sfnt_off000106f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F7 16944 bytes
SHA-256: 66877755f49e3f5fa0a334f01ebed91e602c59a39e8680f04a3c4a623e27051e
font_02_sfnt_off0001333a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1333A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1