Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b681f8f0fc7ae4e…

MALICIOUS

PDF

73.7 KB Created: 2021-09-02 14:56:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 000e36e511eb60682da57b325646c62d SHA-1: 61d3986af5d142d276befdf0b6aee7565b380ea7 SHA-256: 8b681f8f0fc7ae4ee2c9a9309316d9039b0879d5105ae05aeb9449c0f94042e6
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or SEO abuse. The file's structure and URL patterns suggest it's part of a larger campaign to distribute malicious content or manipulate search engine rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://refinerlink.com/userfiles/file/46077912969.pdf In PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/70992377712.pdfIn PDF document text
    • https://havilahbuilders.com/userfiles/file/zopafebaxeb.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/055de5b7a7c2810879c96ac6e413988b/46307839564.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/tamurenejixoregedib.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b1615cd0924---97780589372.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/b26b328a23cb64bb03fa3ac2229f9d64/venidudasutixawim.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/wixinumukag.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f6c76ff1905---fakilafefirozoxubapi.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf04703ce6---lozoxuviv.pdfIn PDF document text
    • http://gptools.net/userfiles/file/dibesedisaxozolikan.pdfIn PDF document text
    • https://ms01bet.com/contents//files/batajexidexafixodun.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/ofc5ccv6eircnm2516qu31m79r/rusobirafabudadesumuwi.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/dusipubak.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/7fa70793bc3b4d520f16bdb86e1563b1/xizerupuvefuja.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/51cebb3e12314fae6407055f275cd022/51054039827.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1611adf3da75df---39685483640.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/da3ce9f9fe53898228ffbb5b94c79d71/33650737551.pdfIn PDF document text
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/87386c916680b2082e881ba042c47487/jepidigejiranovasakima.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/29366919155.pdfIn PDF document text
    • http://planetamama.ru/files/file/61645409066.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/buminizamofudoguboku.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/nulilasamekojajozivopupen.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/7fd2243180043e1b83b49470b78e468f/vinagezuluxur.pdfIn PDF document text
    • http://varosom.hu/userfiles/files/moriwikelu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=farmacos+diureticos+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_off0000bc0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC0D 17476 bytes
SHA-256: a70f4ebd267b17ea7c33ddc7ca8fd4b14df91ac6426e1eb8b9481e4435c25aa4
font_01_sfnt_off0000e8ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C4 10708 bytes
SHA-256: d920a73e7cfc30963201fc6da561168a4cfd5b691a556b04da24a69bdbc8870a