Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bcaa80878881df4…

MALICIOUS

PDF

70.0 KB Created: 2021-06-08 10:43:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 2958bc508f5f10a568f4da14cbfeac64 SHA-1: 7a35ca53db49af2d9f9749015d4ed11dbf411fea SHA-256: 3bcaa80878881df4d8a01f6d2b6b28e06ced7da7a2ca029df2de514916b44c98
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this tactic, and the presence of external URIs further supports the phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=curso+de+direito+civil+brasileiro+maria+helena+diniz+pdf+2018 PDF link annotation
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/0ceee0668e5a13bbbc508b53453807d4/41224834873.pdfIn PDF document text
    • https://iguanapools.com.au/wp-content/plugins/super-forms/uploads/php/files/07qn5af56kigr12iselbbtkdo3/lidabelob.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/4u3ednuli6gq74vohnlcnffvv7/25190541927.pdfIn PDF document text
    • https://mt-creativestudio.com/ckfinder/userfiles/files/27361170818.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16071816968e98---sifefeka.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/1ea5fad7db9493e86f5776573a912b98/kofexafesuzurukapajije.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/0bdvdousi5i6ae1qvqpo6il5p3/58027998247.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd829c5dab---35636966018.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/8c717bfe5bdb741341db88e5bb147f66/80316127415.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16086d97fb0e5c---94801723722.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/43i5l5ic43j1a59n7nki1kmoq6/vojetuxi.pdfIn PDF document text
    • https://brod-plovdiv.com/images/vunarawuk.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/6c5m1mg4n91trkb10kka81psgn/45662036694.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160818e2eb052b---kigob.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33780b0c95---74185485521.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a06e72ee010---38131199168.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE21 6072 bytes
SHA-256: 92d93215445216e29e03bb58bc9f11fd88e1526bca08906b5f85b187cc9207f0
font_01_sfnt_off0000e2ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2AB 12304 bytes
SHA-256: eee12b54b9e7f997807146cd207b653290f08f41998e81494747dc8b49352139