Malicious PDF — malware analysis report

Static analysis result for SHA-256 86b66ca1724f64e9…

MALICIOUS

PDF

76.5 KB Created: 2021-08-17 11:26:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 12300b8c706a2feeedc7106d186066cb SHA-1: ecaa948d0726aafe480ebbbcd2917f27dd20cea7 SHA-256: 86b66ca1724f64e9bda5c423773b0faf8a3df5c349f2592d5b2d4771fc96e8a9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to redirect users to malicious sites. Several heuristics indicate the PDF is part of a link farm hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16086ee6f0d0a8---34880272588.pdf In PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610bfa93a1ef7---xurufedozebukewu.pdfIn PDF document text
    • https://btsis.com/upload/ckfinder/files/fewidilewikotadalonuwimed.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c612b82d4a7---31814138510.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/fafebuvozisag.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608963b2af7ee---nepuwotabulosefibolifozi.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dda10dd6cd1---90922645012.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/831e75a18449002d9efd00b9ed3c1caf/vomawagirebuxatufiloja.pdfIn PDF document text
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160804d317a3a3---miwomemofodame.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/47198600223.pdfIn PDF document text
    • https://mundolibre.cl/uploads/userfiles/files/dabavepeguzifarid.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/29261809043.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/96941898334.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/78505674574.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/57284604492.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/36428726838.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/fa34bb61db74a5c118107a7b0001ad32/83644993638.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160badd6d3fe97---64625074309.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/sfgnle3jcne8fvfkbk1krbois0/25846168663.pdfIn PDF document text
    • http://myafmc.com/clients/a/a5/a51d49d85de18111a3d718c63a5e5081/File/35860466076.pdfIn PDF document text
    • http://friend5190.xyz/js/ckfinder/userfiles/files/wexopurebevefowi.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ad7756f2466---34645921441.pdfIn PDF document text
    • https://thietbidienmanhcuong.com/upload/files/60270967922.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/3h1u73iupr5fhpg2baa7qb94c7/8824859006.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=manual+de+pediatria+hospital+infantil+de+mexico+federico+gomez+pdfPDF 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_off0000c3ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3EE 11324 bytes
SHA-256: c5ee396b91977eecaf608d4894383e184b8a2a565bf4fcd62544cc406a3aec5f
font_01_sfnt_off0000de2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE2D 17140 bytes
SHA-256: fc4a24976f4e1a15c81b0e5f09c54c64db481db4ae44e3508afd2aef31001d95
font_02_sfnt_off000109a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1