Malicious PDF — malware analysis report

Static analysis result for SHA-256 f740e552c592a08d…

MALICIOUS

PDF

82.1 KB Created: 2021-09-20 09:49:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b541d0f3845396eca1d2b703c11dc06b SHA-1: 3172189288870b3ce2ec78b8aa954b3982407a2c SHA-256: f740e552c592a08de4eda3da607aae4385b8cbd0940449911c02a16d79118abb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs pointing to various domains, many of which appear to be associated with compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm designed to direct users to external sites. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic findings suggest a campaign focused on SEO manipulation or redirecting users to potentially malicious destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://medvor.ru/uplcv?utm_term=free+seo+keyword+difficulty+tool PDF link annotation
    • https://virtualpulse.eu/UserFiles/file/96190092873.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/161341ddf72374---vuluxogijidabiragidituj.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/tuditidobuwufogoloduge.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/8senhkpe01s1tf8u70svujbcc4/13978443477.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/6699e7877c57366e097e8c63e7e5a6e3/biram.pdfIn PDF document text
    • https://www.leasing.net.in/ckfinder/userfiles/files/5100700507.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/39608877158.pdfIn PDF document text
    • http://gelateriacool.it/userfiles/files/funikowew.pdfIn PDF document text
    • https://zlato-stribro-investice.com/upload/files/diduwef.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/xogulejakupubo.pdfIn PDF document text
    • https://wanna-drive.nl/files/File/66758061408.pdfIn PDF document text
    • https://brawlcall.jordanadams.com/ckfinder/userfiles/files/29249726017.pdfIn PDF document text
    • https://unique-u.biz/images/uploads/file/70065906849.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/53382048526.pdfIn PDF document text
    • http://crmloccitanecr.com/campannas/file/mezelakawu.pdfIn PDF document text
    • http://costanzolegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/53621960420.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/nerosikasaxazog.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/sls52rht0hlduqrar5rifjdv5m/78831992557.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/61365702544.pdfIn PDF document text
    • http://kimhoatra.vn/upload/fckimagesfile/mojupufexin.pdfIn PDF document text
    • http://sgrappresentanze.eu/userfiles/files/jivinadixepojikivadirejud.pdfIn PDF document text
    • https://dijitalsanat.link/upload/files/revarutovuwupefa.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/60846462133.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393b0bac44f---ziwowurawalinumu.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/3645103714.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_off0000dd59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD59 10572 bytes
SHA-256: 163cdc25bf6c4e58b9d3927391ec9bcd29be133a8d013b9cc5719191b36fcd86
font_01_sfnt_off0000f5b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010dc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC5 17252 bytes
SHA-256: f150719c13b754f8de9f8b1196bcb06aba5520a4d39a7dabc0426643ab458a9a