Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8c37edda2ef629f…

MALICIOUS

PDF

84.2 KB Created: 2021-07-02 10:48:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 7803db40376141355ec7b35c47080c53 SHA-1: 7a6740e2110f6774ea7665b86e7e7e5866b77843 SHA-256: f8c37edda2ef629fb4b93e7832afb077ab9e400fa59bf46c0612e7b9a4c38af6
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised WordPress sites, suggesting a link farm or redirection scheme. The ML classifier strongly indicates maliciousness, and the presence of numerous URLs on disposable hosting further supports a malicious intent, likely to distribute malware or phish users. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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://catamma.ru/uplcv?utm_term=staph+infection+is+it+contagious PDF link annotation
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079d24d3932e---biludizalogidin.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/14bbb1cc579cb2bb84ad153c0994c398/32706019337.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents//files/58091675507.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbd5c323bbc---zakivamijelivawolowebaxil.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609981dd8e7c3---39642811268.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f8678dedc6---64539172738.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/fifajopoderejavufamu.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/f5fcae51008324d5afeeefbe708fa3a6/xojozuvotiw.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16091685cc8f6c---gepokidogiboka.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca0263dac8---64413660106.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/aelt26iqakjbk7mp2qfebhh4g1/10086739178.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/a6a6828ab647873702caed2d1919b903/4356357513.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/253510359.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160cbe8169df8b---91709719737.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3d68c45d6f---19395980845.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cee5ebbfea5---96785680598.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/73d2b473d2a4611bd8cc8674649a034a/20705201329.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b5297b554c---84326986220.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/9ia18j94ag12jlui13mu6no1ht/92136909367.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160c6caea74638---10625857359.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/sidojixesuv.pdfIn PDF document text
    • http://music-summer-courses.eu/upload/files/gunanoxepubiva.pdfIn PDF document text
    • 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_off0000e8cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8CB 16360 bytes
SHA-256: d57633fe0707788eb0239d20293c82ef5d0ab72c0b8033a2c28b33b7bf959eb5
font_01_sfnt_off000112c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012add.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ADD 10788 bytes
SHA-256: 12fc651b2dc5748151346791b9965d2d6b079816918c875c0ce7034d6b6874ad