Malicious PDF — malware analysis report

Static analysis result for SHA-256 36655e9d2560219e…

MALICIOUS

PDF

81.0 KB Created: 2021-09-06 02:52:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 721f500dbbbbad783a59b5229d7b42fc SHA-1: 77b6ccf20015e259182cd5280b99979fb4f5cb39 SHA-256: 36655e9d2560219eb331747233d62a212a9acdeba272f6171c1d70d26d6fbe84
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://almudenafernandez.co/ckfinder/userfiles/Files/86807761624.pdf In PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160acf74811b46---35682917651.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/u9trp11c91tbaao1sm5ja7oasn/sozarerotamovimotekog.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097688fc3851---73292334053.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/80004620942.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bd46420d842---kazedijuvod.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/36867648820.pdfIn PDF document text
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/eq8n8a3frdcvu9142gco39hk4k/nonoxesowokixivivonisafu.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16081532b2dcf4---86375163375.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/80156462078.pdfIn PDF document text
    • http://kengosushionlineorder.com/uploads/files/fegurakumopixujupegunudo.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/ledoxizovofevadigekadituk.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/12625380324.pdfIn PDF document text
    • http://recko.ru/ckfinder/userfiles/files/papepudesita.pdfIn PDF document text
    • http://portableandcool.com/files/files/gokurenedaneguwa.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/ddda674cc1dade9b5f48d8cc036b62e8/zomakume.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/90346123094.pdfIn PDF document text
    • http://waypl.pl/upload/File/dosegajakinexarikilagux.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/26083747282.pdfIn PDF document text
    • http://195exim.com/datas/files/wifelodegesisokuwow.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/lubox.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/14747239801.pdfIn PDF document text
    • https://harteron.ee/userfiles/file/61227846963.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/2854000045.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=gas+treating+absorption+theory+and+practice+pdfPDF 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_off0000d29b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD29B 11144 bytes
SHA-256: f7d2e629cd12a81d4591a211c1d8df4c2a1c1a173a642a0c87993e2be5c38c56
font_01_sfnt_off0000ec35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10447 19520 bytes
SHA-256: 8994b4dca91f894fdb6bace75825bed6d5b7f26bfa8934a1f1d9af7e88d64907