Malicious PDF — malware analysis report

Static analysis result for SHA-256 2018b9cf85eeef45…

MALICIOUS

PDF

77.1 KB Created: 2021-09-11 08:25:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 47eb85e5908bca949dbdde20ccba7073 SHA-1: 5c2102f0ae124ae55d1c948e3ab21b825e818467 SHA-256: 2018b9cf85eeef453ac9571cb6b71c99a99baad048e4cb1309f854985efe19d4
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous external URIs, many of which point to compromised websites or disposable hosting. The heuristics indicate a link farm designed to redirect users, likely for SEO poisoning or to distribute further malware. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 http://savemaxint.com/files/file/xemowarizaxeriguvotan.pdf
    • https://appchecar.com/ckfinder/userfiles/files/65576239957.pdf
    • http://s4l.vn/storage/ckfinder/files/22876140968.pdf
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/9087720a4712f8bb3641a6d1f91a76c3/63100361709.pdf
    • http://unternehmensberatung-hegenbarth.com/userfiles/file/xineduvogud.pdf
    • https://snpwachq.com/files/js/ckfinder/userfiles/files/87997518789.pdf
    • http://sunrui-ti.com/d/files/5715112662.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161315d930b52e---65337877795.pdf
    • http://perfect-aerosol.eu/userfiles/file/24995288115.pdf
    • https://needlugs.com/userfiles/files/zitevexuramatarepilex.pdf
    • http://sinojjacob.com/userfiles/file/ninorolofapiw.pdf
    • http://wannawwannie.pl/userfiles/file/44978775250.pdf
    • https://negaratoto.com/contents/files/fuwagurabifafimazodu.pdf
    • https://greenfins-thailand.org/uploads/file/gutaxewid.pdf
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/24165142974.pdf
    • https://mertlakustika.cz/images/pages/file/domuzebejatirokewaparule.pdf
    • https://northwestconvention.cz/data/files/68088511127.pdf
    • https://synersys.fr/contenu/file/78320513931.pdf
    • http://hidropro.hu/upload/bonolajubin.pdf
    • http://garage-ys.info/js/upload/files/5445009143.pdf
    • http://nghieuphong.com/upload/files/12685566372.pdf
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/19811b10c1faa2dbd8b9e01d4fe4f7fb/kixaliwugufotajak.pdf
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/mumakukezil.pdf
    • http://sitoad.com/bbqjoekey/files/202109110014381722.pdf
    • http://xn--80aejmo0alc.xn--p1ai/ckfinder/userfiles/files/9322128845.pdf
    • https://delta-relay.be/userfiles/file/zewejavimedenusivak.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=zee+tamil+serial+new
    • 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_off0000ce15.bin
2e14eebaf7e3c1d93216cbe7eadf6259b7d26d7fef53dc81b3c13e76a5c25b9b
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE15 10196 bytes
font_01_sfnt_off0000e4eb.bin
c2f4a3f46ea2025aae4323e6f3ba2bf0461a0446a21f555c70fea58fd1cce0b4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EB 16284 bytes
font_02_sfnt_off00010ee2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE2 16792 bytes