Malicious PDF — malware analysis report

Static analysis result for SHA-256 509a82d39062c0e9…

MALICIOUS

PDF

83.0 KB Created: 2021-09-08 23:17:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4dc8d1501c398e91e8f78767ad6acd1b SHA-1: 84c795bd5e75e59d63ebd8955b58fea581975166 SHA-256: 509a82d39062c0e9ab9c0419c1d861d0e880a9bbcb800b6ce99503c9f1a86471
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links, with one heuristic specifically identifying it as a link farm on disposable hosting. This suggests the primary purpose is to redirect users to a collection of other PDFs, potentially for SEO abuse or to distribute further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zlzljc.com/uploadfile/file///2021090201485679.pdf In PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/161300d35d9c88---kaxirobazimezirom.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/64519704875.pdfIn PDF document text
    • https://ladachess.ru/userfiles/file/vojafanakatubur.pdfIn PDF document text
    • https://psystat.net/candyticket/uploads/page_images/files/fisavefakomovojepagixe.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/vct09gtbeiqr8jgj5gnisnqeil/42750250688.pdfIn PDF document text
    • http://filippodelvita.com/demo/userfiles/file/47025404366.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/gupolonewizugopirejo.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/64268232715.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/vojovirujurolubugikifibe.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/34145314779.pdfIn PDF document text
    • https://eastoncn.housemember.com/uploads/files/32585328682.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/88192276457.pdfIn PDF document text
    • http://edisonprivateschoolbeta.com/cote_dor_import/admin/ckfinder/userfiles/files/bosidesotivozudowetara.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/54618701606.pdfIn PDF document text
    • https://quangcaonoithatgiahung.com/admin/webroot/upload/image/files/73822172177.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/budonozi.pdfIn PDF document text
    • https://peintures-descours.fr/fichier/files/meradexeguzakonip.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/91536411093.pdfIn PDF document text
    • https://dogathermalhotel.com/resimler/files/23966585702.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/94089468772.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/jaladexinebotape.pdfIn PDF document text
    • http://fusen-es.info/yamituki-n/uploads/files/sopuvilifawojo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=ubuntu+free+android+emulatorPDF 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_off0000df88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF88 18180 bytes
SHA-256: 09d036b40345fd9c55112d0f87e03abdb16bfdd80a9db62a5cb90b5c502aed89
font_01_sfnt_off00010e3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3F 10596 bytes
SHA-256: 521a7aec7078688ec538c4d5178a0f6ad04eaec6d83eaac54f78e3107de21593
font_02_sfnt_off0001265f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1