Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5ff950b449634fe…

MALICIOUS

PDF

88.4 KB Created: 2021-08-03 20:03:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8fd88c3a3acf47316bce4e12cbb1551a SHA-1: 6dd0d9d16204174b455e88640c45705b716b35c2 SHA-256: d5ff950b449634fe52ff1d92fee84316c5d1672a83dde198f403f375fd46f779
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be associated with compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users, potentially for SEO manipulation or to serve malicious payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://crewmak.ru/uplcv?utm_term=free+online+typing+copy+practice+exercises PDF link annotation
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/minufudenubewavetolufolaf.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202107032046134651.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16095d640a6d4d---vijuraluzaduzigevijizo.pdfIn PDF document text
    • https://siam-royal-view.ru/data/files/lodivazirebezukikezus.pdfIn PDF document text
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c8e54570e---xisoja.pdfIn PDF document text
    • https://tavio.ru/files/file/regiti.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sogujal.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/rfocioqsf7j2hf0rh64v8770v1/modisajivimideratezexexo.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609066a377762---80282590424.pdfIn PDF document text
    • http://atek-ent.com/upload/file/95614163327.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/resinaxulegemo.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/28832660112.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1147ec08d---lurej.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16091b25b67bf4---monuwiponovagezijanexixed.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160796298659f6---58672539961.pdfIn PDF document text
    • http://nonstopsushi.com/uploads/files/buwisupeminejizuferumezu.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6e6efc5da4---zasux.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2263456db---88422370205.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d54f608d9---32174208321.pdfIn PDF document text
    • http://overtonnation.com/clients/f/f9/f97855507a39dfa58978186db9bff07a/File/fobomun.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/jabezunagijaj.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160884d7b5d868---futikutodel.pdfIn PDF document text
    • https://www.almuhja.com/ckfinder/userfiles/files/wironak.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/p65f84gvml34pv9rn7jr31ka0j/zowexegevakovolupabesoxi.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_off0000f5bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BC 10740 bytes
SHA-256: d46612615369d2d1104b365d9152b9bb08768cb3ff7f188cf56001a99b7abd16
font_01_sfnt_off00010e90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E90 17392 bytes
SHA-256: 408c2495795ac861946da9f010cd169b7d069a8b9d30c01299c0a65e0bcbd055
font_02_sfnt_off00013b8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1