Malicious PDF — malware analysis report

Static analysis result for SHA-256 a16a4e8bf549f116…

MALICIOUS

PDF

97.6 KB Created: 2021-09-10 20:28:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2623dd3f8c3781c7664ebdd46b939ae2 SHA-1: 3d284a3755ac1f1077986407b1dc4f29aa711102 SHA-256: a16a4e8bf549f1166ba5295113381e1bf403c0a68dd5245a33c84818d9fab230
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ev-owners.jp/userfiles/files/40112952361.pdf In PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613989460ee4f---bupesomek.pdfIn PDF document text
    • https://airxps.com/userfiles/files/5971590762.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b105245836---97337748636.pdfIn PDF document text
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/53236430609.pdfIn PDF document text
    • http://khocabien.com/uploads/files/zibazifurodurukupapujuto.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/41354257592.pdfIn PDF document text
    • http://vanprodukt.cz/UserFiles/File/luwasukiju.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/7e4bab3ifp4vu0s7udctskbld9/zalimowaxuxezikanuxi.pdfIn PDF document text
    • https://turdv.ru/SITE/files/editor/file/bokikabadalobe.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/74562083372.pdfIn PDF document text
    • http://balbu.eu/uploads/news/file/goronemesazojexogumelu.pdfIn PDF document text
    • http://fcvperu.org/data/fcvperu/userfiles/file/rujomusukemakijedege.pdfIn PDF document text
    • https://bisleriuber.genefied.co/ckfinder/userfiles/files/75792296251.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/41a0to5hu0jbbkdufr0av1mfp6/wodatalif.pdfIn PDF document text
    • https://mahae.hu/files/files/taboxulukaruzibamusez.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/37434712512.pdfIn PDF document text
    • https://anna-bel.com/app/webroot/files/userfiles/files/96625762841.pdfIn PDF document text
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/70095383710.pdfIn PDF document text
    • https://proia.bg/userfiles/file/22187947208.pdfIn PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/37790340397.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/b916b94c7b27770418f56ca84b5ace58/86449458886.pdfIn PDF document text
    • http://atsrealtyvietnam.com/upload/files/vafidujurogimevopos.pdfIn PDF document text
    • https://ojazzdance.fr/userfiles/file/75184064395.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=id+code+for+fishy+on+mePDF link annotation
    • 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_off00011551.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11551 19528 bytes
SHA-256: 2d202fef90fb33610f5368f46d7e1a4f7f390164b7074a00ce9cc8588910bcb2
font_01_sfnt_off000148dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148DC 10500 bytes
SHA-256: 6708d06238535184e3b1113d15e4607f27639cc655fc73cee6ac476f850065a0
font_02_sfnt_off00016085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16085 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1