Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a68d233f8079b7…

MALICIOUS

PDF

76.8 KB Created: 2021-06-27 10:49:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 6e1b6199120edb6642fc5dc4dc73f37b SHA-1: 880adbc6f8ea2a1599d6727aea457f071c0541e6 SHA-256: c8a68d233f8079b7ffe0f29e5bcbfd14c366897b7947ef375a476a9ee0fd6961
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to manipulate search engine rankings or redirect users to malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://krisoc.ru/uplcv?utm_term=sql+if+where+statement+in+select PDF link annotation
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/42c90ea876973038962467c0ee2671b7/82540916942.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf2141d0ef6---renud.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088cc5aba2e2---lerakapofilenedug.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/038b08d64c5eccb439ca0688ef711f1a/20568137498.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/64142260400.pdfIn PDF document text
    • http://goref.ru/files/file/33639334431.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bdff809beb8---zemojizadotunu.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160afb6de43c4c---tonuriro.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/282c8cafb3f0c2b1ebefffb195d69093/14403786906.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/63f0f72cde41b8ab15f3fa6a276710e4/sawusigare.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bb0bd25ddc9---60474614421.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076b4211c6bb---xomijewewono.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/ids2elsib88de49s5ljt9iti24/pelejamolosevaxosokejo.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160941d87d9de5---watofiforixaximakon.pdfIn PDF document text
    • http://xn--80aaae7amexjfdlfdfg.xn--p1ai/files/file/95875419367.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160889d4bd3b18---lurixujivoxu.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083d34ebdd9e---62412274366.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/42030671523.pdfIn PDF document text
    • http://psychoterapia-przemysl.net/img/userfiles/file/37945980342.pdfIn PDF document text
    • https://lapdonline.org/file/75420278039.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_off0000c609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC609 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1B 17548 bytes
SHA-256: 6172b9957ee742355bee658b1bba594d67355466f6a3992c714eee8a35036982
font_02_sfnt_off00010bde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDE 10788 bytes
SHA-256: 5d00db617950e0c4a2dcf9c41af12e7d693401afc6ae4bf62092742197f4e15b