Malicious PDF — malware analysis report

Static analysis result for SHA-256 c850853fe80a072d…

MALICIOUS

PDF

94.7 KB Created: 2021-09-14 00:23:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 26b187884b20728f452dde9849d4b766 SHA-1: 34047f417802bc535656c04ba57a2d6980a4c4dc SHA-256: c850853fe80a072d2bc5c0b8199c1914c14b3903b1ece5ec2529b6ba94a637a4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external links, many of which point to compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of creating numerous links on distinct hosts, often with UTM parameters, suggesting an attempt to manipulate search engine results or direct users to malicious content. The embedded JavaScript and the nature of the links strongly suggest this document is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://crysiq.ru/uplcv?utm_term=call+recorder+apk PDF link annotation
    • https://gamma-electronics-eg.com/userfiles/files/sawib.pdfIn PDF document text
    • http://agro-vostok.ru/userfiles/file/44965683984.pdfIn PDF document text
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/40869571552.pdfIn PDF document text
    • http://pnc21.com/files/fckeditor/file/6876383256132d844d653b.pdfIn PDF document text
    • https://autoskola-scp.com/files/wadelulas.pdfIn PDF document text
    • http://on-video.com/movies/movie_data/file/botalagazurokotigege.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/713f3971167bb97f46a8da331467859b/40820662086.pdfIn PDF document text
    • http://saddabro.com/userfiles/file/duxivuvusew.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/fotojatunodaxuzugeder.pdfIn PDF document text
    • https://sardavetri.it/userfiles/file/19408534929.pdfIn PDF document text
    • http://girlstown.org/files/js/ckfinder/userfiles/files/kijibedibosezojataxi.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/jabadubowuxiregetewuxoko.pdfIn PDF document text
    • https://tomaszbizon.tomaszbizon.pl/web/uploads/files/7573525317.pdfIn PDF document text
    • http://chukguwang.com/files/fckeditor/file/10581556529.pdfIn PDF document text
    • https://asiahealthcaredentalcentre.com/ckfinder/userfiles/files/waxumetamefunafiwasozi.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/revujenonadovifune.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/pepizadoresimujini.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/21112172208.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9d82e36a5---viviwuzopozuwav.pdfIn PDF document text
    • https://sitpchemcieszyn.pl/_sitpchem/file/58259808291.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/84547937521.pdfIn PDF document text
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/mugibogerubateva.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/64668689210.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca11d61db8---90227415622.pdfIn PDF document text
    • https://shreegroupco.com/userfiles/file/35543077468.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_off00010897.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10897 10168 bytes
SHA-256: c393b3e2612e8050af86b7f855a533f47b80d32998ac88b9da5d8f4f06d16d6a
font_01_sfnt_off00011f6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F6B 20124 bytes
SHA-256: eb5be06f76d127a220efb4047f9b6437b23604a4cedc90dfaf5776a70ff2fd75
font_02_sfnt_off000154f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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