Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c527f96fef56c1…

MALICIOUS

PDF

70.7 KB Created: 2021-09-20 22:52:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fc9332cf53a5c470d69614a74c85961a SHA-1: 0f70711c06c370b6c2780d9dec68006dd4d64702 SHA-256: b5c527f96fef56c158c3525722e9bfcf3e2f0340113293ed00e5cd3c887eb307
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to other PDF files hosted on various domains. Heuristics indicate this is a link farm on disposable hosting, with some links pointing to compromised CMS upload storage. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware through the linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ancoraeducacion.com/images/60475903798.pdf In PDF document text
    • http://oishisushigd.com/uploads/files/zivawinotonetexozoziw.pdfIn PDF document text
    • http://rem-stroymont.ru/img/file/46663582044.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/fubixokizivu.pdfIn PDF document text
    • http://aescantabria.es/upload/fckeditor/file///zurobogojivomigavinizo.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/c406e93bcc2af99de034682d1d65bf30/93227448428.pdfIn PDF document text
    • https://ventadeterrenosagricolas.com/userfiles/file/31022987573.pdfIn PDF document text
    • http://mwcapital.net/ckfinder/userfiles/files/79075586439.pdfIn PDF document text
    • http://gesgo.de/userfiles/file/tubuworinid.pdfIn PDF document text
    • http://nepalbestcargo.com/userfiles/file/88536781481.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/kowidolof.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/rezejijamuvizidegeteme.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/rejiwewelazalepud.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/85413554016.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/33468748433.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/41461258174.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/33422003430.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/83315332730.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161461cc10a050---40391399055.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/24590587809.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/161362a25479a9---68485149796.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/99146430756.pdfIn PDF document text
    • https://artbynela.com/uploads/file/tofebavavesemela.pdfIn PDF document text
    • https://gilboamedia.com/userfiles/file/negiboxevizowexakezodamij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=mk11+mobile+hackPDF 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_off0000b3ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3BA 10304 bytes
SHA-256: 035ea295b828d2c7fcab47784ce0305b47675f82538a48c98f5e9e9b179c745e
font_01_sfnt_off0000cae7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE7 16644 bytes
SHA-256: e6bec694b55907809cd7e1e68cc5149b28304ca7eb323dd0ba0663d69e94f81b
font_02_sfnt_off0000f5c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1