Malicious PDF — malware analysis report

Static analysis result for SHA-256 13c28f180d1ba3c6…

MALICIOUS

PDF

76.0 KB Created: 2021-05-01 11:44:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: da58a5fcd3daf900db866e647efadd59 SHA-1: 2550ce1e753061bdc024a746c544ba34c34bf604 SHA-256: 13c28f180d1ba3c63fead2034cc031d162f0292ce80383ba83889f2e838c0f41
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload directories and other potentially malicious sites. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest a phishing or scam campaign, likely using the 'father christmas letter template' lure to entice clicks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/p41afquj6f0ucc2ifj1kqrs48d/2280839134.pdf In PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/c47834473668ccf0ce37024dfcbd51c6/83540768876.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607c337b026fa---78443236037.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb2c1a1fdd---64095407852.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/c22aad5cb5425e8e6f351554f82a0c67/ledib.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160726eb1423f5---61049845688.pdfIn PDF document text
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/5aide6anvmibjg5i9usrmm7amk/97515322949.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/bca4a2a0920cc5c620e2df81a3736926/96431358048.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fbca5a87e7---5207609838.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/v71qfm2l4clpiqc111132fq9la/mijusosufetojalokatom.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/8k2iku9rgb9jod3chq8jgr5dor/47607456891.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16075c7f7530cb---sivimodirefu.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/89634492136.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606ced308d898---81550764672.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/b3754c64a5c52342b4b5cdb71fd899dd/4700628851.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/001b809163d93bc030ba8315efdeee45/josokad.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16071a85db98d4---segejulimuginuwuraravatij.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/1ea25aa47cd2ee95beb611630daf7ec4/luduxudetifegerular.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=a4+father+christmas+letter+templatePDF 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://scripts.sil.org/OFLIn 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_off0000d72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD72C 5332 bytes
SHA-256: 66538309085a7835c7281b57f02d3a8315a44d80206cc7d8f3cdae3a51e381b1
font_01_sfnt_off0000e92e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92E 10408 bytes
SHA-256: 963581dcddf04562b21ad477d9a68361a60bc1fc0938a20af63f38b5384db641
font_02_sfnt_off00010d05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D05 16312 bytes
SHA-256: 028dbaa76d48ae99b02248bacea50134e27ed131f5dd39e25ac401de8961e19b

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