Malicious PDF — malware analysis report

Static analysis result for SHA-256 b23f98291ecf59b7…

MALICIOUS

PDF

68.7 KB Created: 2021-09-19 17:54:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0fa593f4eee581d21670f41f418c8184 SHA-1: b20bfc383ec72042d29642c518e5a0c4b3116e0e SHA-256: b23f98291ecf59b79e888e25804064e69db83b57b10ef372aa275911a3d9a269
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. The embedded JavaScript and link farm suggest an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://allytemp.ru/uplcv?utm_term=primary+4+mathematics+textbook+pdf
    • http://0851gay.org/userfiles/202109file/2021090914285170554.pdf
    • http://gaestehaus-am-erlkoenig.de/img/editor/file/nulukoxujunowumewolufuw.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/5bb34ec6a68e0c0a6a24c3935272c75d/13639042301.pdf
    • http://studiovalentini.eu/userfiles/files/xopamikujaj.pdf
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/ff4e12a24cf70f7be5877f88c63cca52/430971345.pdf
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210911_174514.pdf
    • http://tevukasveza.lt/ckfinder/userfiles/files/vofonuva.pdf
    • http://hotel-gerard-dalsace.com/upload/document/85777103850.pdf
    • http://qcfloor.com/userfiles/file/ruxaxojuduvakolese.pdf
    • http://doggystylzgrooming.com/admin/photos/file/17208907512.pdf
    • http://tydafa.com/dafa/uploadfiles/20210908161002.pdf
    • http://88cpap.com/userfiles/files/14721357267.pdf
    • http://adidravidar.com/ckfinder/userfiles/files/33269259477.pdf
    • https://mkontakt.pl/dat/file/12769948369.pdf
    • https://winstar-tools.com/UserFiles/editor/file/farugeb.pdf
    • http://www.mostex.sk/files/articles/file/nutimataxexasuvokowanenot.pdf
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/70491801952.pdf
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/c43cbfb68bbcdb16af500666a20c9b79/nefobowaxuvazefivugiwim.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/9dcueor1l2hcim40t6pbraomi3/60800545564.pdf
    • http://nhac.ditimchanly.org/Images_upload/files/83477145327.pdf
    • https://moveo-sport.pl/userfiles/file/kupukebazelejozijizumi.pdf
    • https://chatsystem.site/js/ckfinder/userfiles/files/78402914280.pdf
    • http://sevenseahotel.com/uploads/images/files/saxopasaburuja.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_off0000afb5.bin
ff61cb6bdda164043a72978c48322c74c23bcd6cf958cb10a9175e8ec9bb8013
pdf-font-stream PDF embedded font (sfnt) at offset 0xAFB5 14168 bytes
font_01_sfnt_off0000d2c8.bin
e01a7d0ae149b8b586ca06410df531ca7d3fa00f73b5e4afe5171a24fceb88ec
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2C8 11260 bytes
font_02_sfnt_off0000ed18.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED18 16792 bytes