Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca336e484504559…

MALICIOUS

PDF

92.3 KB Created: 2021-09-13 06:59:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 48a2ad020887a4850c2a56d844499b28 SHA-1: 5e11cc7396240d390c62387d1b277eb9b0c94169 SHA-256: 4ca336e484504559a2ea972cbdaa462c3abd698c555c37a6b3a5e42f3a79e059
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document that contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver secondary payloads or conduct phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://nomylo.ru/uplcv?utm_term=como+ser+huevon+sin+fracasar+en+la+vida+pdf PDF link annotation
    • https://trickapotisk.cz/webpagebuilder/ckfinder/userfiles/files/87407984554.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/38532102186.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1613eb05c083e8---sokujope.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/somujusixodozefowiwi.pdfIn PDF document text
    • http://seychelles-resort.com/images/blog/file/zudafuramutebufupew.pdfIn PDF document text
    • https://blagoustroystvo24.ru/ckfinder/userfiles/files/41594992775.pdfIn PDF document text
    • http://ayurveda-shiatsu-qigong-nice.com/upload/files/tafolemebuvad.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/42163681415.pdfIn PDF document text
    • http://edeins.com/userfiles/file/70120929091.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133a94353c79---11875139319.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/sidutubasosajedubefozi.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/lowonokulesirivab.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/xurekewufaxobab.pdfIn PDF document text
    • https://predial-rua-nova.pt/056-CovadaLua/images-editor/file/vibizajapelidama.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4567004967.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/gigejowamawe.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/10037590209.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/96743274806.pdfIn PDF document text
    • https://livstyle.ro/home/livstyle/public_html/uploads/files/geduzibazor.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/77659924337.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/2018939950.pdfIn PDF document text
    • https://aristi-trap.com/upload/users/files/49813417761.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/gesikepizubid.pdfIn PDF document text
    • https://hirurgija.me/files/lexuxemivemew.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_off0001011e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1011E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11930 19144 bytes
SHA-256: c3602a043acd51177ff7d3ea041570cbfb195ae6454dc6b03ab29f46dd540be1
font_02_sfnt_off00014993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14993 10984 bytes
SHA-256: b28abad9e7a9d84aca26fff1f015eeceeb0b692bf9c7fc643d2be7ac425fd931