Malicious PDF — malware analysis report

Static analysis result for SHA-256 a23bcb29627cdf5b…

MALICIOUS

PDF

89.9 KB Created: 2021-07-17 23:06:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 30ca38ce9ef37a497acd3051d46c969a SHA-1: b00f9310f2dc0e0a238f617732f405c4e7b7b74d SHA-256: a23bcb29627cdf5bc8981acf4730d77d9a1bbfa866d9a8ba30df100ede5d706b
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or directing users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://honyi.tw/ckfinder/userfiles/file/15341563306.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4d6983ffb---rikesonunateg.pdf
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/58cd6d83ec5c50711eb8aa5771e410d1/kekukem.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e73cc506c---48298545669.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609eb1893e435---6936289922.pdf
    • https://dbjadow.pl/attachments/file/wobatoparupisolunelawolad.pdf
    • http://fletcherfamilyreunion.org/clients/52745/File/pevopeziburesavix.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a13a4f45e01---96197292118.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/21799b2e102df14e0d271b0a312b1072/depuj.pdf
    • https://toolsatool.com/userfiles/files/75081229064.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a27618c777e---nadozobotagokutamifobe.pdf
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b3744ebc93e---51412715640.pdf
    • https://actorconseil.com/files/file/77738860110.pdf
    • http://alliance-ltd.com/userfiles/demotatejukibogumirixun.pdf
    • http://fixafilm.se/userfiles/file/jabejodigiluxevaw.pdf
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/261ile390a3ssq201duhfkl729/gotoxisemobovugulo.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e593cebc739---pafujep.pdf
    • https://www.andrecampbell.ca/wp-content/plugins/super-forms/uploads/php/files/660d3ef46938ee66e0e32dda9409e157/posolalisexupol.pdf
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/7o3q4gru8v811vpd0gi36b4qsd/52229736929.pdf
    • http://bidmitt.com/img/files/file/xisumu.pdf
    • https://mcitalianwine.com/file/kezobodaxazewemesazedun.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a8dea3c5210---rozigidufox.pdf
    • https://vieclamkinhdoanh247.com/upload/files/50194005147.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/4d671d019197cf4170e0f137face095b/90971955465.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/9fa7a906b57f6ff65334cd0c11f2516c/zipegobafobujigutoxil.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=small+self+introduction
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd68.bin
fb39165f7ba66f0f820c454775fa5cadfc87b185a2e400ebf8f64bf2c65946c0
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD68 16928 bytes
font_01_sfnt_off000129a9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x129A9 16792 bytes
font_02_sfnt_off000141c0.bin
983fbb5df8e364d4f2a2a8b2e770c71c3aec9f0aaca02e92b831928fc987304a
pdf-font-stream PDF embedded font (sfnt) at offset 0x141C0 10812 bytes