Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b9f9043686912c…

MALICIOUS

PDF

82.5 KB Created: 2021-09-01 04:49:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 7fef0c7479af19e89892a9934194aa17 SHA-1: 97b01487537c5d57e907a4985a2aa9166bbf7a21 SHA-256: 51b9f9043686912ca149da08a1a73229c5f54531a7e93ca6abba56f0003727e3
156 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs and links pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The file's structure and numerous links are consistent with a malicious PDF designed to lure victims through deceptive content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nomylo.ru/uplcv?utm_term=neuroendocrine+lung+cancer+icd+10 PDF link annotation
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/nm8s6jmu075vdea7prkg6mc4j9/maxexexerewagesibij.pdfIn PDF document text
    • http://gevenschoenen.nl/ckfinder/userfiles/files/63224070478.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/witinizu.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/xinotuzepigejifetoka.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/ttfrnggnb28lb9ppuea75gb13f/titimavev.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2a9b03ee41---51773574886.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/79969771720.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/tapiganiv.pdfIn PDF document text
    • http://synowka.pl/galeria/file/vezuze.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae93ed55ba5---39302988814.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/161d22742fc2e3f89825b1d32667234f/pitorawatupiwovavepotele.pdfIn PDF document text
    • http://spec-so.ru/sites/default/files/file/bimapevufuliri.pdfIn PDF document text
    • https://almavilag.hu/files/files/92217174975.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8591fdeb1f---23759316258.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/oipg9b5siiroe87mlq7dr7ta9e/88690703681.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/xeboronexi.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8b2f45320---kuveli.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/71627275358.pdfIn PDF document text
    • http://centromp.it/userfiles/files/kubaxigusumiwefojas.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160752d6d47817---86951244782.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/el7hlnr2h1suptehcnrehacqre/24093839283.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/98027667998.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_off0000e1dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DC 10532 bytes
SHA-256: 7cd81e1471641ee823ec94afc60c9e0115707a4bfe44d5571d593e65830cc454
font_01_sfnt_off0000f9b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B5 16300 bytes
SHA-256: 8f1df702147192ccaca420ffb3cc8ae4c748b0e24db4b69f619a7008973cade6
font_02_sfnt_off00012424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12424 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1