Malicious PDF — malware analysis report

Static analysis result for SHA-256 de557eb238b9c5b2…

MALICIOUS

PDF

85.9 KB Created: 2021-08-10 20:28:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c17b3c77771e01800295f8ea2e70ea65 SHA-1: 25df8dbb8db6b96ba4bf7c7b6275d0c1ab7bd17d SHA-256: de557eb238b9c5b2c71aafd576698f37400ed1c91735e253635cd763588e467d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file detected by ClamAV as a phishing trojan. It contains numerous links pointing to websites that appear to be compromised WordPress installations, suggesting a link farm or redirection mechanism. The ML classifier also strongly indicated maliciousness. The primary attack pattern involves directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/uf16765b8pka1hmsah8fjsoldk/76940072177.pdf In PDF document text
    • https://muguet.fr/sites/default/files/file/32057096994.pdfIn PDF document text
    • http://zuche0551.com/upload/file/zatidilexutatimolaxepovi.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/944c757a69ef75693046b45414009df3/xuvivajevogo.pdfIn PDF document text
    • https://technoray-medical.com/userfiles/file/xugorod.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160777afac7a20---18306586878.pdfIn PDF document text
    • http://hms31.ru/img/file/53350136808.pdfIn PDF document text
    • http://thecoferfamily.com/clients/7/78/7892d776c92a08c80f86ebc6236678d2/File/92520714602.pdfIn PDF document text
    • http://atol-res.pl/uploads/file/ximalisirevovun.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/mujigibibipamez.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e97c5cbdc---vedurugapebogoto.pdfIn PDF document text
    • http://madiran-cruduparadis.fr/ckfinder/userfiles/files/vizosubejesifuravidubuvof.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021070122490073499.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b63800d1610---fesosanulo.pdfIn PDF document text
    • https://tigercabinetry.com/wp-content/plugins/super-forms/uploads/php/files/b82380ab65bd2ad6c600bcd01189548b/gezopijewuzevulewosupu.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a402569dfa2---fofokurakigazajibel.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/741e3ff5f0e0caf1bfd40e16436af75d/14770453063.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/7878528897.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210620124847.pdfIn PDF document text
    • http://tktravel.shop/FileData/ckfinder/files/20210604_5B8C364D9A31A88C.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607040964b093---26994461061.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607377f4c58c6---12890349113.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=define+reflexive+verbs+in+spanishPDF 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_off0000ec68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC68 10548 bytes
SHA-256: 5392b74ca7062c0a8eb8e72a499b1ee96aeb664f678bc0ff8f921a070512aeee
font_01_sfnt_off0001042a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042A 17704 bytes
SHA-256: a8001cf9cdfb9ad264be077873e14e0b658c2038ef3e239e0e9e75e9f5796f2f
font_02_sfnt_off00013136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13136 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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