Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae90f9f5cdeff9a7…

MALICIOUS

PDF

98.5 KB Created: 2021-05-10 19:28:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 789d76facdd203080f5729335cbf002e SHA-1: 54858b96f0c058675e4834199b76c5168688d0bb SHA-256: ae90f9f5cdeff9a7fd9707004a7c486ad5d49841c1ec97fdcb27f17da08ba00c
156 Risk Score

Malware Insights

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

This PDF file was detected 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 multiple compromised WordPress sites and other disposable hosting domains. The embedded URLs, such as 'https://medvor.ru/uplcv?utm_term=learn+ms+excel+pdf', are likely used to distribute further malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://medvor.ru/uplcv?utm_term=learn+ms+excel+pdf PDF link annotation
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/d8d08d9bd1f794267c860adbb9af6f06/63036958083.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/7f435c0e8836fdb8f921ca605fe901be/81962232745.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607446318ea7c---80752999186.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2ea88a454---vefitajijezu.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160940aefa262c---mexugirite.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/wizodefew.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160883fc122b63---geludezidu.pdfIn PDF document text
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/f34enni66mh927m4kg7jk686cc/lupukalaj.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/93cbde5b70df00dd9a60897952e87d40/lolewogefamube.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/54b5e9da9b5d81c9500ff7faaed29987/liliwenedipemewip.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/rmbd9echfja5q429sseob0fk8f/dumezepo.pdfIn PDF document text
    • http://fouladsazanco.com/Upload/file/zivugunipojetigakur.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4a1527abb---wipiponix.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/h2a8mnkrnvkn2778m45q66qdl0/basonuvojuxinurew.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/9a144c4f857d8b54d36a5e20ca19bed1/19369852810.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086cb4e60e8e---wanupatedegov.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001449f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1449F 5312 bytes
SHA-256: 02717a524d84859d3f9e6469c2df023be7f3b4630ad8559d9b2178a8fb5cae2f
font_01_sfnt_off000156a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156A4 11512 bytes
SHA-256: c1d498df31c2dd48e08bb2244ff41ee32c97c9f40e9c25cdb096863fc1746770