Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d33e6d9b6bc1821…

MALICIOUS

PDF

83.1 KB Created: 2021-09-15 15:17:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf3f6586c249e1ad478171893e6787cb SHA-1: 1850a286ada9e911338d3dcb4517270740d6620d SHA-256: 3d33e6d9b6bc18214ea035f4e2c2f310a04613297c3c1c1c438b4e5b88abed90
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are identified as a link farm on disposable hosting or compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://chcial.ru/uplcv?utm_term=what+does+se+for+android+status+mean
    • https://gotoko.com/cmsv2/upload/files/502315634.pdf
    • https://windsbs.biz/files/file/99219962954.pdf
    • http://cuacuonbinhduong.com/upload/files/71635528144.pdf
    • https://clinicamanila.com/ckfinder/userfiles/files/3235956867.pdf
    • http://perfect-gallery.com/userfiles/file/dezuwofumilunuwonamiga.pdf
    • https://yam-token.com/business_school/uploads/file/remafik.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1613f28a6f3bc0---65709584136.pdf
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/8185577083.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e3f953f5f---lezolizunidikupodemo.pdf
    • http://ssatripoli.org/userfiles/file/72809046408.pdf
    • http://monthclean.com/uploads/files/202109042102535878.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/edb6423ecf7a15d7d7b7b36f862c13a0/fumirunetonov.pdf
    • http://caphegiabao.com/upload/fck/file/kitopejevagezusatojal.pdf
    • https://seerupit.dk/assens/file/94339012319.pdf
    • https://lecormier-menuiserie.com/www/upload/files/7318613537.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613b89664117b---pozoje.pdf
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vatevasotanamalevolijem.pdf
    • https://atlastoursntravels.com/userfiles/file/wemepu.pdf
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/9389bac82261f3ac4df0e905e010880c/zisokuvezumunofefatajo.pdf
    • http://labmansour.com/app/webroot/js/ckfinder/userfiles/files/15902851606.pdf
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/55351605571.pdf
    • http://needychild.org/ckfinder/userfiles/files/29333724742.pdf
    • http://kme-kme.cz/files/file/69892659493.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_off0000df58.bin
fbbf363f04b85473818bf12cd663ea8c4c1d43314ce6d397d23f3178bf1c1b95
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF58 17948 bytes
font_01_sfnt_off00010e1c.bin
13f5e58b37fe17811476bd0cff6c262588fa5b14224071411e26bbeb3eaa2136
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1C 10668 bytes
font_02_sfnt_off00012669.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12669 16792 bytes