Malicious PDF — malware analysis report

Static analysis result for SHA-256 a16df9926ebfecba…

MALICIOUS

PDF

94.4 KB Created: 2021-07-07 15:48:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ca606ed6f2e7c89e4d2592356525b8d2 SHA-1: 88ab79c3d18eb31bb987fc5e5db9e93795388ed3 SHA-256: a16df9926ebfecbadcf6c989860660fb717f5ec763fff63897df97b4fa3b0f5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it may exploit vulnerabilities or employ JavaScript to facilitate the redirection, aligning with common phishing and malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://ranaghatpchsschool.org/userfiles/file/fetazibuzigosu.pdf In PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a641094dadf---44540897633.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/ddsgk43ajg01k7escjqd84a281/lujibomused.pdfIn PDF document text
    • http://lyjclinic.com/ckupload/files/50435024108.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/xagefibazuso.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/tt37gclef8fura3acnpf3hplfl/xibipaxelibogekuxusoji.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/8b7p11138irlf1ktoduf2d76mi/nulixidakaxe.pdfIn PDF document text
    • http://samtekelektrik.com/files/gotusolu.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/o5al8emt619889n8q06pohbt36/xidixapu.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/89758614937.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eab16140a4---givaduvagakapubipuva.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160d931fd1a5e1---99918823468.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160881d8846ed3---45394342493.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/29335901186.pdfIn PDF document text
    • http://dlzj.net/upload/files/20210616002852634544.pdfIn PDF document text
    • https://reparation-mobile.net/userfiles/file/79513417889.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f0ccc3ac8---55078142220.pdfIn PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/juwonufowevulazawukaxaju.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/bedb6a07a6cb621aaf31a1dd5b532a07/ruzerofifumutuzepo.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/5bc81c13f016e7d75d103866e4cd2184/15671342890.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0b2548e7---48753545321.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c88b43394ca---sapojizusud.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/7fo02c8lomr8t4bcpo8idkjagi/zijufibukisabefubuz.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/pelaruxutomedatokiduroxa.pdfIn PDF document text
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/8c661329123d6f86e742a65f9cfc3a2c/29875648133.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=academy+store+hoursPDF 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_off00010d92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D92 17740 bytes
SHA-256: a1ec770ae8506c7a0c8fd68a20ac5451f4116de61c7cdf01f0a9bc9c3d89e73b
font_01_sfnt_off00013c36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C36 10588 bytes
SHA-256: d3eb7340b3fab0beb3d132dff440a0a44d13db26a9f9238167fd127cbc3dccf5
font_02_sfnt_off00015486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15486 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1