Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef624c875e123545…

MALICIOUS

PDF

79.5 KB Created: 2021-09-03 21:28:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 66782c949ecea6d6d8c0d392276f849d SHA-1: 097d2403536a65df36e2a03f39e7ae22366ae16d SHA-256: ef624c875e123545aab3119d9668aaa2b6301de9753b3b14904bb90f514cb06a
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to various websites, many of which are hosted on compromised WordPress installations or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9844

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://irlanc.ru/uplcv?utm_term=vet+parasitology+pdf PDF link annotation
    • http://lsneotek.com/ckupload/files/nexavukifedokob.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d0c9ca8e3c8---6256491385.pdfIn PDF document text
    • https://torgradio.ru/new/files/file/54352135091.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/1a2fea28f9cf3e7d16a1ba0ee1eb618d/98138207360.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a86164802---66762813159.pdfIn PDF document text
    • https://tenekedjieva.com/uploads/file/rofen.pdfIn PDF document text
    • http://duralinealu.com/upload/files/satuwibakufusogametaloxa.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea84fec629---92595772761.pdfIn PDF document text
    • https://landbondcorten.com/attachment/file/29b1aa588ad801ce7848d7ade5eeec84.pdfIn PDF document text
    • http://chromowane.com/userfiles/file/34470417502.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160dd68d6c2e7b---segikogujanoxidetokik.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/7e2f97f387429759079bbcf67ca9e066/masugazuf.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb7009d855---3254689417.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a928a5b5192---zaxig.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/jolugeridi.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/zedebonagupukinad.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/xilapitovejomu.pdfIn PDF document text
    • http://drukarnia-warszawa.pl/pliki/file/modepugefelomugajunigax.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160aad1269f362---kabipaxika.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/e0sbe38gvs72pd3cgefdlp3jkf/jemoxi.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/33631052301.pdfIn PDF document text
    • http://fairview66.org/clients/866114/File/15308429412.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/girodimesarivivomufuk.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/nemetekunixewedugukuli.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f08f05f21b---mufefok.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/9f0efa1b2ad29ef2c7e41e3212ad0661/74127356380.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16077a55120e44---37507412345.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a23e8778652---gifutidanipe.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_off0000d1bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e9ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CE 17708 bytes
SHA-256: 97c413ab00a5ace17e9b1e42e3cf72f063b704397a1c0f18d3f06a9ec6239eb7
font_02_sfnt_off000117e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E6 10652 bytes
SHA-256: 204b6cee9ef854a572fc786eaa0bad16885891f38a07543d29e6b7fc800e6af3