Malicious PDF — malware analysis report

Static analysis result for SHA-256 721f6d81d91f3b21…

MALICIOUS

PDF

71.0 KB Created: 2021-04-30 02:49:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 2597243acc7605cc4f4006c24f7f811b SHA-1: 92f0656ec36209f1774bc19e584d99682d5e79fa SHA-256: 721f6d81d91f3b213043b455a3aea52553a875be18759711a22e3c1d1b91ee37
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised WordPress sites, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. No scripts were extracted, limiting the analysis of direct execution capabilities.

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 http://ajtoablakcentrum.com/_user/file/jefufinenal.pdf In PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16077834aeb982---91571794787.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/c1c082b65b7aea8a160d65782b6e1069/29501397205.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/160780da07e0d2---48881807480.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088089494622---97352576863.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/4ef5b68cb375259fa850c9750669563d/92265053377.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/5bac0e7cd9451f387e4ce6164885e3f5/74509339254.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/9cb747e1319a61a147ba4b97ca7d7323/pegawebilajov.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/bf8c36u897vg0k5a193nketp4o/73677551589.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/2ie02lfecj8pm25b6hj8uuf4rk/jofedaxajavupojejanamuxef.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082039031583---15329383051.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16082f2c84a59d---rerujaxidekajujo.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4a2309880---21145701313.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad36a97160---10454699372.pdfIn PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/1f0549c10a3ab2a42d41deb5fc197ce9/lizotexafinifip.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7c3440876---vowebimuvozeri.pdfIn PDF document text
    • https://www.ideaklinikbursa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607610edb7531---koxoxadapaduw.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/GLLx1DTH0VQ/uplcv?utm_term=platform+economy+chinaPDF 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dae8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE8 5048 bytes
SHA-256: 4c85d0a44eb2dc7481616f40681756fcb328cb9ce5771d14d6a2625663d913f5
font_01_sfnt_off0000ebf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF6 10352 bytes
SHA-256: c185f572a457c8a42068c734d8a81ce41e98c670191c691023c511638632d0b6