Malicious PDF — malware analysis report

Static analysis result for SHA-256 35b754389db262c7…

MALICIOUS

PDF

91.4 KB Created: 2021-07-07 17:30:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 822dbc5b716fb931c8427675c8192810 SHA-1: 402db081b1004ce93160769a052449532d0c380a SHA-256: 35b754389db262c763871da43b58e4bad0bcc0c534e29414596ff141d6df48ca
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. ClamAV and ML classifiers strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://kameleonhastanc.hu/files/file/sijos.pdf In PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c792de6de4---224365971.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/3a1f6204146afc32be362d9fc5cc61d8/46311007518.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160752df4722dd---63740402861.pdfIn PDF document text
    • http://landpas.pl/upload/file/84556145967.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/6b86763ac0f503e5ee5ce12fa0288917/toduxekoxukixir.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/denonumutedow.pdfIn PDF document text
    • http://hesexpo.com/img/editor/image/file/fuzikejepokanuzivizes.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/0d7519d661abf25e4625d10df286b5e3/tivikexadavunigafovi.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf7c7e3115---nidolivenin.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3782cbdb98---tusaxomatarovafowof.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/79619213116.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160c699cfef03f---40467025645.pdfIn PDF document text
    • https://cafesca.org/ckfinder/userfiles/files/58361698998.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/16079e33a66103---21984560827.pdfIn PDF document text
    • http://prinsart.ro/uploads/files/21563053989.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160de0afb10632---79780181885.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/60327714811.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/bc0n7b66nlkohrg11og1d2n48e/36765600442.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/ce304864f8770c7c35cd7d5df2744120/ruzitasukokafivinerosif.pdfIn PDF document text
    • https://jackyrouxmethode.com/userfiles/file/fotavekifun.pdfIn PDF document text
    • https://tailormade-sales-marketing.com/userfiles/file/63335430064.pdfIn PDF document text
    • https://yuss.it/file/46574169920.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7666801c83---reduzetit.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/juvimexewu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=class+3+english+lesson+5PDF 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_off0001041a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C31 10528 bytes
SHA-256: a62b136ecb3afe7d9ce1271833ef62478b688f9687ac9a6a37799c441be8db19
font_02_sfnt_off00013416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13416 16972 bytes
SHA-256: 6d5694314b4c6d6e294524647ad7384953adeca73376c2763f9ffb4b31f45857