Malicious PDF — malware analysis report

Static analysis result for SHA-256 df156db97121c90b…

MALICIOUS

PDF

79.9 KB Created: 2021-09-19 14:58:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 6a98cc96a5176983889d6074f1b1c658 SHA-1: 309d302c5229b8338bc578fcf96bfdc68ddab906 SHA-256: df156db97121c90beb87ed3b35ec20707750a25945de5a167366318529803fdd
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains an embedded JavaScript stream and numerous external URIs, many of which point to other PDF files hosted on disposable domains, indicating a link farm or phishing attempt. The embedded JavaScript and the nature of the links suggest an attempt to redirect the user to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://coretry.ru/uplcv?utm_term=how+to+control+my+android+phone+from+laptop PDF link annotation
    • https://araprinter.com/ckfinder/userfiles/files/6276039094.pdfIn PDF document text
    • https://woft-dining.com/webroot/editor-uploads/files/49268516505.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/devisufutanobaz.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/nokunesupe.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/8346307892.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/relokuzataregamaveb.pdfIn PDF document text
    • http://happysmilecard.com/uploads/files/sugujilud.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/7390717961.pdfIn PDF document text
    • http://k-ookuma.com/js/upload/files/74752672390.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16143b5f8e64c4---kitikipilivopoderiliwij.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/laxikasibegubetewegakis.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/hdbmq3kn0cc6ek7sqp7b6lgnu6/8267599249.pdfIn PDF document text
    • https://hobbyschuurtje-webwinkel.be/images/userfiles/file/wegazadasiligaxojujaz.pdfIn PDF document text
    • https://villanakarin.com/userfiles/files/17442305271.pdfIn PDF document text
    • http://xn--rssx31a7tec6p.com/upload/userfiles/files/20210902010848.pdfIn PDF document text
    • https://rotitelor.com/contents/files/zijezutozifiziletaje.pdfIn PDF document text
    • http://gatewayhotelbangkok.com/upfile_hotel/files/43910156325.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/ralapa.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/48426559862.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/54590614638.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/87722822287.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/18405626966.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_off0000d314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD314 17696 bytes
SHA-256: 2201e5eca0d444927ee410394beae9f7271562e45b9644340c1b8cfafb2b11f4
font_01_sfnt_off0001006e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1006E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11885 10908 bytes
SHA-256: 9e4a2a0329c403f1e0343e656da79f4033d6a9262b2eaa73b96dfc44bc1092e9