Malicious PDF — malware analysis report

Static analysis result for SHA-256 655383eac88d65f4…

MALICIOUS

PDF

85.7 KB Created: 2021-06-26 00:50:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 68f3f9508352e4f028dbde7531687d28 SHA-1: bc60215ecc09dd938fca84669c4a9ce6e0045458 SHA-256: 655383eac88d65f48024dada64bf52b1bc1e4c924b865c0de9be863473027c87
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection indicate this PDF is malicious. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the document is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 https://krisoc.ru/uplcv?utm_term=executor+of+the+estate+of+the+late PDF link annotation
    • http://vodnik48.ru/content/file/81203743667.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096430e53c7a---xigurijutowaminitaremepu.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dq0ic8h30ap427jfrkns2ut9a4/rasulororumakusuzemake.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f5280ac582---metetepejivedoxazu.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/00958ad92000341903434f3d9dfe7f40/ziwowomiwukexolo.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/712ec75b2d23cd445df698e09f99c5e1/wanolupusa.pdfIn PDF document text
    • http://kangs78.com/clients/66216/File/ponurolefumudo.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160858b17d6cdf---zoboxemowa.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160784be526aab---21622040350.pdfIn PDF document text
    • https://circolodelpistone.ch/userfiles/file/4110739532.pdfIn PDF document text
    • http://kaies.cn/upfiles/file/73710376685.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/bokijulakil.pdfIn PDF document text
    • http://freeski.hu/freeski/file/gokabezodilutitofolobem.pdfIn PDF document text
    • http://pokewaveanaheim.com/uploads/files/nimoxizege.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a1d2e4228---dazugokar.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/terinigan.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1607854971e312---suvuwoguxiboxagoruteje.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/71263dd2f9070bfd6e59b1f8e12005ea/rodidanodowotis.pdfIn PDF document text
    • http://chinhlytailieuluutru.com/media/ftp/file/kosojogibe.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///desenafedinupur.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/woxatutur.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16076f4c0d9e97---33008561369.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/b528288de4d18b2e8a20142c24421df0/ponadegugasazegavozi.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/se2rp8ehpp6lmk6hg57if57ap5/movamewokez.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/wupositoxef.pdfIn PDF document text
    • https://kovosluzba-praha.cz/res/file/35929474386.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_off0000ecf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010507.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10507 10420 bytes
SHA-256: 8d00526e8c9b4e433fa868b5a62c57a3a16309461c2ee7ab9dc31452483f9cd4
font_02_sfnt_off00011cdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CDF 17012 bytes
SHA-256: fc1f5b78185fc7b48509d44de0807c388ce1b976edc72ca9624e0812100d8f9d