Malicious PDF — malware analysis report

Static analysis result for SHA-256 1e73e1671d812b1e…

MALICIOUS

PDF

87.7 KB Created: 2021-09-02 08:34:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6d8e100a0cf4662fa12c05ab755f0441 SHA-1: 03902cfde0e885b3822fee97be14f40a0b101b57 SHA-256: 1e73e1671d812b1e21bf90f63ee34057239978a03ba4423d57da82ea78ad9833
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution document. It contains numerous external URIs and links to compromised CMS upload storage, suggesting it is designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the presence of numerous links and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://medvor.ru/uplcv?utm_term=how+to+underline+in+a+pdf PDF link annotation
    • https://nevisnews.com/userfiles/kadebivijanevoboja.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/49641009830.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b1eebe8638---likibawurisupez.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/xawenitiwewolazirukoguzim.pdfIn PDF document text
    • http://thanhlapcongtykiengiang.com/upload/ck/files/zojofovetuma.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607841d4e5d4a---simejagixuwogorixisuxifid.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/tajupixoladafumarufaromu.pdfIn PDF document text
    • http://stevis.cz/files/file/96830060483.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608ecc54c896f---wiwokebotubebined.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/90831384131.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/2n5q7da1p951fepf24hd922ga1/kofeluwif.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/61789222756.pdfIn PDF document text
    • http://insidethedigitaltrend.biz/userfiles/file/16787577681.pdfIn PDF document text
    • https://airshow-bg.com/file/gobosevitozo.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/0hu183kmg15l0oufnfvoqn3j05/fudaza.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/10486903577.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/12626758011.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/musafekuj.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16117138e9a8bf---95583286020.pdfIn PDF document text
    • http://normel.org/files/upload/file/10390175355.pdfIn PDF document text
    • http://dyweisheng.com/uploadfile/file/2021080304433073499.pdfIn PDF document text
    • https://j26clean.com/upload/files/bikinavivozorivo.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/57dc9d7c79ddd30e20cc51f7d84d962d/lujirezedezot.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/20455708349.pdfIn PDF document text
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/42fosasnqvm8hfrpr2p8dqvi9i/xinadebav.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_off0000ef34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF34 10500 bytes
SHA-256: 30d2fe65e24e1a156596345b6e4446a8bea5610f8a3575d0b233929fa11e9edc
font_01_sfnt_off00010728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10728 18920 bytes
SHA-256: ffce969c6dc30a983e6cbb1ba83d1484c65df725d9cf6f497a5798ce4002ed2b
font_02_sfnt_off00013867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13867 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1