Malicious PDF — malware analysis report

Static analysis result for SHA-256 79b67d821d63b56d…

MALICIOUS

PDF

73.5 KB Created: 2021-09-20 21:44:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1b3f03fb0eaac48dde28df714aa72fdd SHA-1: 915c9f37870e965e902621db9dc9de811d391202 SHA-256: 79b67d821d63b56db6e91c3495b507c15e797030995a2310db0440c6272a9f39
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the execution of JavaScript to download or redirect to malicious content. The presence of multiple link farms and compromised upload URLs points towards an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ketchas.ru/uplcv?utm_term=class+11+book+biology+pdf+download
    • http://raegcafe.com/uploads/files/6114796823.pdf
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/supizotef.pdf
    • https://www.agencesramos.com/ckfinder/userfiles/files/56075234349.pdf
    • http://ximangsongthao.com/app/webroot/uploads/files/88839793739.pdf
    • https://299-45.com/CKEdit/upload/files/18959425211.pdf
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/famadibuveguxuromugafun.pdf
    • http://myucpb.com/userfiles/file/luwupotan.pdf
    • http://soyaksiesta3.com/userfiles/file/41224053104.pdf
    • http://hyundai-dongdo.vn/images/files/93993217064.pdf
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/1d88131c08f6f69e2b1a9ae81a803202/40756013026.pdf
    • http://portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/sobir.pdf
    • http://bsp-oblspl.org/ckfinder/userfiles/files/filudejebadot.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/37dea8eb0619ebf3da8e847e2a2bd331/19448692052.pdf
    • https://vieclamlaocai.vn/webroot/img/files/rofonemifipiwu.pdf
    • http://wellnesszeewolde.nl/site/data/ws/files/daxedakisebaw.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/edfc7a9da7a54d87ed1a9e6320f35afc/bobimifududilojusebugo.pdf
    • http://finalstage.biz/js/upload/files/27002083125.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614090c1d1384---bomajokani.pdf
    • https://dottoridegregorio.it/public/file/rawusopopunejo.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/j8v68o5lcm6ki7idqv0904qeq4/73616668318.pdf
    • http://dreamsurgerycn.com/ckupload/files/pafowubata.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/1u6efc4scm6dq4gash85fpae72/86527170183.pdf
    • http://thegoshow.net/userfiles/file/ferirugatupa.pdf
    • http://sydjpg.com/images/upload/file/20210905_120458_176.pdf
    • https://varida-tech.com/ckfinder/userfiles/files/41326939838.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_off0000be14.bin
c6c1aa84364e3f69d7700299345bf4c9bdd924aeb23cd0d1c38591731d2be69f
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE14 10860 bytes
font_01_sfnt_off0000d6f4.bin
48c6ddfc66c66a23d063453b304d885b754412605664be07b0f31ef76f95fd30
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F4 16120 bytes
font_02_sfnt_off0001002b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1002B 16792 bytes