Malicious PDF — malware analysis report

Static analysis result for SHA-256 52a139257108770d…

MALICIOUS

PDF

73.0 KB Created: 2021-06-20 02:59:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 141a5ee2341d8bd234d848e2be003c47 SHA-1: 6c4694acc026bcdfdf2989f6104d95f147659167 SHA-256: 52a139257108770d97800ec6ac2afa3c58c526ba5305096584b257221850e01c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to potentially compromised WordPress sites, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of malicious activity, likely serving as a delivery mechanism for further compromise.

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 http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a345f72b5ef---77380217268.pdf In PDF document text
    • http://stewartreunion2020.com/clients/2/2a/2a0d9dcdd57715375c9f4393c24df0f2/File/19333482096.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb4f906cb3---vimolokizezejurudekube.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/d9964ad0d23d72a4d713762a105dde2f/mutikutekenafamujijijix.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/47b8176bdea3c1fe5e80af3e220d4291/92818108618.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/benodinifof.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/019220577fc34678dd9b54ece38ed806/15929407122.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16081f02ce6db2---34181986972.pdfIn PDF document text
    • http://cokhitienvuong.com/uploads/files/1176226799.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16099f624b1741---52874938682.pdfIn PDF document text
    • https://bednidhitraders.com/userfiles/file/dusuxenofe.pdfIn PDF document text
    • http://amajyuku.com/files/files/66716817720.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/lazesafejajufat.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfa63ae670---lokimibufuxevovedu.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/e8a85c6b06ac1790338bf8b6462f0d7a/besiwelufu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=crash+of+the+titans+ps2+romPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB7C 5144 bytes
SHA-256: 329ea6a29523b682fb1350778d7a1b6c905bbd56fe0b6d958628bb52dddcd159
font_01_sfnt_off0000ecd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECD1 12644 bytes
SHA-256: 9fa7f3317fdbe9802f23d80ecaff18919b895beca364ac1392d5da3f5cbda712