Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ef7aee9bf51a509…

MALICIOUS

PDF

71.4 KB Created: 2021-09-15 19:12:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 74528b4c81bbd0c26d77ecc14718b4f5 SHA-1: 71a24525661fdb3ec0f363a9714dd7366e40ef7c SHA-256: 7ef7aee9bf51a509a38dc03851474dfb31171445cd32d04f2cf3a8a87c1fc001
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojanized PDF. It functions as a link farm, directing users to multiple external PDF files hosted on various domains, which is a common tactic for SEO poisoning or distributing further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://barsugo.com/ckfinder/userfiles/files/87034976891.pdf In PDF document text
    • http://gayaarchi.com/userfiles/file/20210913201037.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/zifunonemizenepewivo.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c3cd3d713e---jodedizimulupekif.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/kufiwidolowa.pdfIn PDF document text
    • http://ldkxzzs.com/images/userfiles/file/tapomixeneduluru.pdfIn PDF document text
    • http://naso10.com/userData/board/file/67524271555.pdfIn PDF document text
    • http://artsar.pl/userfiles/file/18084669037.pdfIn PDF document text
    • https://onecre.com/images/content/files/nokotojilexefe.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/68629831996.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/redufelaxiruwikake.pdfIn PDF document text
    • https://www.totalblissbeauty.com.au/application/third_party/ckfinder/userfiles/files/xasevaxafejukifobem.pdfIn PDF document text
    • https://xn--80aesyq.xn--p1ai/files/file/bawegakonolarunoferalaru.pdfIn PDF document text
    • http://medwin.kr/userData/board/file/33866823085.pdfIn PDF document text
    • http://www.depomatrial.com/file/60361017074.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/78226256195.pdfIn PDF document text
    • https://ontogepszerviz.hu/editor_up/68014642292.pdfIn PDF document text
    • https://jokerprod.net/userfiles/file/berosanazulekir.pdfIn PDF document text
    • https://usssecuritate.ro/userfiles/file/rebukivezuzizemipizaj.pdfIn PDF document text
    • https://okazionche.com/files/6068944740.pdfIn PDF document text
    • http://nhagiatxanh.com/public/default/ckeditor/files/3799541988.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/b1e679e5f80a41afa516e85456c631e8/2869099194.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/ruxiko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=boruto+episode+184+english+subPDF 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_off0000b60f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB60F 15896 bytes
SHA-256: 43c5c56cf07d8832ec75190b36a3d3f284ac73b474586b14fb2b2af6007158de
font_01_sfnt_off0000decb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f6e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E2 11140 bytes
SHA-256: 42ba2b0798a740d36d46a7751e9f28b9a59eb1e73d328a2fc067e87450e4f073