Malicious PDF — malware analysis report

Static analysis result for SHA-256 8936852c5e8c6f51…

MALICIOUS

PDF

83.4 KB Created: 2021-09-23 05:34:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66f5ade64d0034db5645dd8b901e22dd SHA-1: 801922feba009a076f7ff3fb21527c24b138fa2c SHA-256: 8936852c5e8c6f511528ab126b32edfd1fdf2d1bb3080dbead93543f7fec8477
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded JavaScript, though not directly executable in this context, indicates a potential for further malicious actions if the PDF were to be exploited. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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://krisoc.ru/uplcv?utm_term=5+largest+countries+by+area
    • https://chptravel.ir/data/file/kijekasadomebudip.pdf
    • https://zakarpattya-tour.com/upload/46812998939.pdf
    • http://veganogle.es/uploads/ckfinder/files/40815148309.pdf
    • http://www.park-seversk.ru/other/js/ckfinder/userfiles/files/jiwafesaxavepifejino.pdf
    • http://playitdirect.ca/ckfinder/uploadfiles/files/vikatasuzosotixusiwit.pdf
    • http://lnhaihui.com/userfiles/file/20210913142340_1739037110.pdf
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/lilulegovuweme.pdf
    • https://camgloberealtor.com/userfiles/file/51749406988.pdf
    • http://smwiarus.pl/ckfinder/userfiles/files/sakedura.pdf
    • https://interference.ajoda.eu/userfiles/files/27254480233.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613412d542549---32613815440.pdf
    • http://mybyblos.com/userfiles/file/44091235100.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140a4b186fcf---tusunas.pdf
    • https://xehowo24h.com/images/ckeditor/files/23940020822.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/4lpj4lbclvmohdvk7eupif2jul/26304098543.pdf
    • https://rezilta.com/psum/admin/userfiles/file/misosagidenemujiwapelu.pdf
    • http://lukinserv.hu/file/73527999906.pdf
    • http://softwarefactory.nl/images/file/buvatufikojufe.pdf
    • http://thayloilocnuoctaihanoi.net/upload/files/32929898250.pdf
    • http://ledins.lv/cms/file/zavakofodepojugojawan.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614312d4ecb88---fepalutokuw.pdf
    • http://africanhairbraidingsalon.com/userfiles/file/pizaremarezuzoluketupuveg.pdf
    • https://wodepcb.cn/uploadfiles/files/21617804105.pdf
    • http://chretkinia.pl/userfiles/file/1063619716.pdf
    • https://sentinels.ro/userfiles/file/rezawusifamoneti.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_off0000e049.bin
f7ef00bf9b8ee0106fab45245b74553d779a05ba3449da869b63357fbafd2012
pdf-font-stream PDF embedded font (sfnt) at offset 0xE049 10796 bytes
font_01_sfnt_off0000f950.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF950 16792 bytes
font_02_sfnt_off00011162.bin
00ea9513fd979ed7cafea0413d771f19ca97cac033ab30095a65967b351171e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11162 17872 bytes