Malicious PDF — malware analysis report

Static analysis result for SHA-256 f621584db9237992…

MALICIOUS

PDF

86.2 KB Created: 2021-09-06 02:47:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a6229c46f7a590b0026e2b85c679aff8 SHA-1: 64ed18047021b6fb6c77c19c35997f70ce7169c8 SHA-256: f621584db92379927ccb47e5b11089f13e5242fe5eee69346f00207a3b822116
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various websites. Several heuristics indicate this is a link farm, with some URLs pointing to potentially compromised CMS uploads. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or SEO abuse. No scripts were extracted, but the structure itself is indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cremyco.com/app/webroot/docs/file/bixesopufezukagewalaba.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/85dc2e647123f799c97f1f010a04582a/29264933234.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/ncrmiu41fcougp158thcae3vih/49382040720.pdf
    • http://didula.com/img/file/25871370791.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e3afcfc75---doxibidatozozilazevo.pdf
    • https://nodka.eu/ckeditor/ckfinder/userfiles/files/52575739598.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160f1efa968eed---76327590671.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/d15dbfc83533d5523aac4999ca13de9e/15463406266.pdf
    • http://standrewsparishhighschoolclassof1964.com/clients/70428/File/41840362952.pdf
    • https://thietbidiensino.vn/media/ftp/file/79472231010.pdf
    • https://casadko.fr/userfiles/file/daviputozowubolomirubur.pdf
    • http://etcad.net/np/upfile/file/52142952967.pdf
    • http://fredericjean.net/oplusco/file/dixusisoranizemusesibed.pdf
    • https://pui-vital.ro/msg_media/file/wopojatemufok.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160718d20a586e---sugawejapiduzexazitofofos.pdf
    • http://isvpro.com/custom/files/vozivekuxijizaw.pdf
    • http://servmed.net/userfiles/file/50806422251.pdf
    • https://electrabicycles.pl/app/webroot/uploads/file/16250493468068.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6a3e75570---pudabusogul.pdf
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/noxupigine.pdf
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2a75adc76---mepivupopojulokavozam.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/5786681a72d5ffaead24e6b914248068/gowuk.pdf
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a4e10fd9d---50399298498.pdf
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/c51r44198htb577co474i9u3i1/megepuxuwezitefuvujowut.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=current+issues+in+mathematics+education+in+the+philippines+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eafe.bin
b66b4c0c78534c0347859ea2d30fa19033ebc780e30785fec419856979f8f5a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAFE 17780 bytes
font_01_sfnt_off000118dd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x118DD 16792 bytes
font_02_sfnt_off000130f4.bin
6a6ec6362746a2d00e4d97f8e3215306ff3f1952bbb8ce3c38f8f1d8106f3e96
pdf-font-stream PDF embedded font (sfnt) at offset 0x130F4 11016 bytes