Malicious PDF — malware analysis report

Static analysis result for SHA-256 527dac7cae94492e…

MALICIOUS

PDF

70.7 KB Created: 2021-09-11 12:20:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 398a1c6d1f8ceb6e165a3b9cdbdd5a9d SHA-1: 241acbe23bf65259153a8faed95d24f213df7b7f SHA-256: 527dac7cae94492e2bf1e6db07220e5050e340228b42b05b53e22dde0bbb548c
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript and multiple URLs, flagged by ML classifiers and ClamAV as malicious. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document's content is designed to trick users into installing a fake browser update or extension, a common tactic for credential theft or malware delivery. The embedded JavaScript likely facilitates this lure by executing malicious code or redirecting the user to one of the provided URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://synerhu.ru/uplcv?utm_term=google+chrome+apps+for+android PDF link annotation
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/pasutufapuguxe.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/929775243dbc0c15e70f74c18a89edbf/momerolazidakib.pdfIn PDF document text
    • http://mega.kz/media/upload/files/44268768962.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161346b7db047c---woroxiwefapumot.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/4221280243.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/vupalasiwiluk.pdfIn PDF document text
    • http://travelspace.pl/userfiles/file/vosudododemozevifogu.pdfIn PDF document text
    • http://plovdivweek.com/app/templates/js/ckfinder/userfiles/files/zimifedusave.pdfIn PDF document text
    • http://ylplj.com/ckfinder/userfiles/files/58426089767.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161382f712156e---lukijajofaridulat.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/24982019381.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/84596701020.pdfIn PDF document text
    • http://stnicholasway.com/userfiles/file/92169046734.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/falewatabagasij.pdfIn PDF document text
    • http://lica.plovdivweek.com/js/ckfinder/userfiles/files/71622067737.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/rokagufepulazasavituvokok.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_off0000b113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB113 16692 bytes
SHA-256: aa74f2f7f48ff466273e3fbee8d6665243e9cb8ecf0ee881b98db13b0e9304c8
font_01_sfnt_off0000dc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f43e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43E 11008 bytes
SHA-256: e7f1bb6e990876523e30bdc1219c076f03532ef7cc44a759bbd8abca63921fef