Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4c3dd811f109b06…

MALICIOUS

PDF

94.8 KB Created: 2021-07-29 22:44:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c3920a09b205b586d6f71e7a9336449b SHA-1: 917d40b00d6972f158959d226f45f0a0ce10ddbe SHA-256: b4c3dd811f109b065656be7a5b90bf613db38d7c820b8fb1e41d4dc4ac8459ab
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=the+death+of+the+ball+turret+gunner+theme
    • https://aymexco.eu/ckfinder/userfiles/files/93662734645.pdf
    • http://xn--d1achljw0b.xn--p1ai/content/upload/vasifokumusazusuto.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c39b2ac53a---pilatututepuxukavuvufoj.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ce5002c813f---bugopipirulareda.pdf
    • http://studiosiriosrl.it/userfiles/files/80073477204.pdf
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/1c59d4751894e8e80c880bfed7fa3910/somovuvejiwinurewotawa.pdf
    • http://english-life.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca461a893a---gegisuwamawopiduzuwo.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160d2f1adc6259---99551229489.pdf
    • http://jaatkinson.com/userimages/69748547472.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/4329i7arjrdd8gtjl4hg6ip8t8/93694040073.pdf
    • https://alteanetworks.fr/img/file/84130932923.pdf
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16071224ab6638---87245291698.pdf
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/b1e0f428c62112f635cdd828bfb8c6a0/gogulim.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160832767899b7---koxapuzipiva.pdf
    • http://playbabydoll.com/userfiles/file/zibiwesikakakitoturi.pdf
    • https://thokhoavietnam.com/upload/files/19415440307.pdf
    • https://bio-obst-und-gemuese.de/userfiles/file/63488870100.pdf
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/negabesusutodoze.pdf
    • http://schokobrunnen.com/idata/80566372954.pdf
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2073606f7d---69620582118.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c0cb85ad0---pulomex.pdf
    • https://planet-for-events.de/userfiles/file/38641103663.pdf
    • http://sosnovgeo.ru/userfiles/file/fasajeki.pdf
    • https://west-holding.com/userfiles/file/wemodebedorebe.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_off000110a5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x110A5 16792 bytes
font_01_sfnt_off000128b7.bin
038a3f74ef513923d30b88453e0bfe970b5ef4de6111e323d9dc9f13e32a8178
pdf-font-stream PDF embedded font (sfnt) at offset 0x128B7 17220 bytes
font_02_sfnt_off00015594.bin
7ad34f82c39b27ce5220a96ceab55b41ae5ba727f0399d41e5b1a6b0585a571c
pdf-font-stream PDF embedded font (sfnt) at offset 0x15594 10744 bytes