Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83a1d95286c6ec7…

MALICIOUS

PDF

83.0 KB Created: 2021-09-01 10:58:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fb0bb6efdc05b3fe3ca2dfbf91f6d4d2 SHA-1: 28260d1c284e402f997202e0d271ed91702eed6d SHA-256: c83a1d95286c6ec7c999a049c18f677c07350cff76e983ff920ce2963c827816
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of multiple links on potentially disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afe0884ac55---50850849993.pdf In PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/gufiwiditixune.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/luradupezarobusoralifetu.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ice1ksvbs5h5rl3mouq1lcjsuj/36483501960.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160939f72ea415---64545253223.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a85eed35682---59277158133.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815912d1f9d---jujeroroseda.pdfIn PDF document text
    • http://abw10thstreetne.com/uploads/files/34555592813.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/96243959913.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/c9304624536bdebd8ed922cef691e843/jimavekojonubebofafakow.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/d37baea54799afa384ddecc7ec9507aa/buxotinizowijutonetogab.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/70399991839.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/vusetujodufani.pdfIn PDF document text
    • http://huron81reunion.com/clients/f/fe/feec28e48c841af8be4ad6373737a022/File/mugaleserepebagog.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/334fe4010d54af61aa94eb536f7c773a/rudemirijuvowe.pdfIn PDF document text
    • http://www.bash.cl/media/file/tuzinezuzomomumeb.pdfIn PDF document text
    • http://lycee-elm.info/userfiles/file/feditos.pdfIn PDF document text
    • https://transport-vehicules.fr/userfiles/file/midedomunoti.pdfIn PDF document text
    • http://uro-medical.pl/zdjecia/fotki/file/16334214670.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/45508141867.pdfIn PDF document text
    • https://fruzsiflame.hu/userfiles/file/92626403410.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160c992327e53c---guwofe.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160af0f3b10a0d---dasokojumesatalekuwafak.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/56692b1e4076531b30c893cca0cead4c/bopanuvemezejadelusux.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/7ea9bfe1c88b924ab78d74330221e8e1/wexuwevesijufuvasivozovag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=most+expensive+kirby+puckett+cardsPDF 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_off0000de53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE53 11068 bytes
SHA-256: cf812f3dc12aa789ecfee6067df85291a43d26bfde55be8a8cb8b43f58cac3d1
font_01_sfnt_off0000f823.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF823 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011035.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11035 17616 bytes
SHA-256: d9d05eb911c61aa84f7e5fcafe075be6ec8787bc4d8b7d0cd42174404ad95b95