Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcef14ce9669f98a…

MALICIOUS

PDF

81.4 KB Created: 2021-09-14 01:31:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 46773d4f7e287054c4260711d718716c SHA-1: 90b3c203bc7f6b8963d84dfddfb4e2fad08f7fad SHA-256: dcef14ce9669f98a939cf6f084287a62f2c5e7a42adf34512709b15c4e715aa0
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on domains associated with compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external malicious content, likely for phishing or malware distribution.

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 http://all-premium.com/user_file/files/78988312879.pdf In PDF document text
    • https://inprovitcolombia.com/ckfinder/userfiles/files/pitokupovusapupoxim.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134598689e1b---80533308330.pdfIn PDF document text
    • http://aguito.madteam.net/ckfinder/userfiles/files/39309331530.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/34092337367.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/ep57k4vurs1gdks1f9d69h7ck0/peligapovivigipo.pdfIn PDF document text
    • http://www.haztartasigepszakuzlet.hu/pics/file/46007416032.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16131b9c8d7306---berafegunenelujipijox.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/47439590862.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/sejarelopol.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/26274274019.pdfIn PDF document text
    • https://o-dance.com/upload/files/51496555363.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/pozufus.pdfIn PDF document text
    • https://yukkumpulgroup1.com/contents/files/razidoje.pdfIn PDF document text
    • http://rooptex.com/uploads/91347091330.pdfIn PDF document text
    • http://local-minicab.com/survey/userfiles/files/75546236197.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/e424ba2ad8d7061b19ac9e278546ecba/73479736712.pdfIn PDF document text
    • https://cartolmania.it/file/31174531182.pdfIn PDF document text
    • https://andhimazhai.com/images/files/rojukesemujoriz.pdfIn PDF document text
    • https://casalindasbakery.com/ckfinder/userfiles/files/56709176178.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/jisipolowaluzixaxerati.pdfIn PDF document text
    • http://bikaji.zohukum.com/ckfinder/userfiles/files/niloronogokod.pdfIn PDF document text
    • http://ototavandosemesi.com/resimler/file/19949960673.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109070006349690.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=gacha+game+japanPDF 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_off0000dc81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f493.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF493 17176 bytes
SHA-256: cc5dd41a50cfef010654781e6afd5dd40bf9e674405128b19f61a8bfb70477b1
font_02_sfnt_off000120bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BF 10368 bytes
SHA-256: 0b52247967f863bf6705f108999a90f760cabb8710f849bcfed0594d77109839