Malicious PDF — malware analysis report

Static analysis result for SHA-256 539a579c4edaf9a0…

MALICIOUS

PDF

79.6 KB Created: 2021-08-19 04:45:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: be0140b1eca34c3926850234094c0584 SHA-1: 09ec880f1e85f2bca4c1ffbab925580f445eaca4 SHA-256: 539a579c4edaf9a0ffff3b50e718ac9b6daeca709a4cbd3cac445bf22942d6e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised WordPress sites, suggesting a phishing or malware distribution scheme. The embedded URLs point to various PDF files on these compromised hosts, reinforcing the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b89b4e568f3---2582586901.pdf In PDF document text
    • http://minhvuongthuphap.com/upload/ck/files/divuxafixukodopir.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/77657731162.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8677987d9---tekusodovifotomixubixi.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/5030737512.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160abe3d0e652c---98529986632.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/78275472687.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c0842b8aeb---parijogamupisaka.pdfIn PDF document text
    • https://cristalensi.com/public/File/zewowitijitijelad.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/160aa78907381c---8168898799.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/7q526691as0skj9qv4p2j2shs3/bawanujife.pdfIn PDF document text
    • https://cvconstructionsgoa.com/pharma/admin/userfiles/file/67325737341.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf83af8d15e---zizazijerawomuvegi.pdfIn PDF document text
    • http://royalproductsonline.com/userfiles/file/pegakajepopidarilabemufub.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents//files/vuwudidovatexaxiw.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210508174745_830715060.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/bubugunugevufedolaxopuwe.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/24602534482.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d625bfb8538---jutepabokuxafulupof.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/8d2d900ccc2db3de32994024a53ab5e1/64639986243.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/85853554008.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/kokumenubunil.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/75673123695.pdfIn PDF document text
    • http://proxima-design.cz/files/file/novami.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/05a4fa9008343d05fea6bee0b85d72d8/tevinur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+reset+puzzle+for+xenophagePDF 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_off0000d43b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD43B 16440 bytes
SHA-256: c9149c728ec295cc5bbd5a6451b020c859717cf9e415887c96472ea0da077895
font_01_sfnt_off0000fe83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE83 10884 bytes
SHA-256: 606d446f8318062cfaa3626bdc505a255f4149be40b4bbb05b6c3e5f34aca319
font_02_sfnt_off000117ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1