Malicious PDF — malware analysis report

Static analysis result for SHA-256 aac3c3a76d76bcf2…

MALICIOUS

PDF

67.1 KB Created: 2021-06-10 05:54:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 32eb7dbe7e7de255322ef1b926f4bd9a SHA-1: 6906bd115f68b7c47bfe01d9adf97c0c1c94ff98 SHA-256: aac3c3a76d76bcf2666aacfde6e84f738e3ee26d367a9ec30082bd9147d2835c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded URLs and the heuristic findings of 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' confirm the nature of the attack.

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://huntic.ru/uplcv?utm_term=fundamentals+of+plant+biochemistry+and+biotechnology PDF link annotation
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160729d0814575---33586352416.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e03d367fbe---zawubarikukapifuwexep.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/1ddgjhh7pngg6d3go3i5vc100g/bativenerap.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607580c2bf333---37565579058.pdfIn PDF document text
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/96bf68be953d4193cf3834e84d753e88/miketarufebubela.pdfIn PDF document text
    • https://alutat.com/data/file/japatexegunololinawo.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a42b3e8c62d---95116196174.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f83d302108---latogas.pdfIn PDF document text
    • http://anandtouristcorporation.com/uploads/vewenutiluwewat.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/82211860679.pdfIn PDF document text
    • http://canphantich.net/Images_upload/files/gubewokivaweki.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa32f531c2b---76531463911.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/81462398955.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160826fcf7ff00---52469917333.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/94300727177.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080299e708e8---zuduponebiv.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/80346bac75c134389705357a993380cb/91155623156.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_off0000c835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC835 5764 bytes
SHA-256: bb5ed847bf657461a15a35eee2e1d0af0df415a4fd13f4ed1049059a17685c60
font_01_sfnt_off0000dbb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB7 10416 bytes
SHA-256: cf74532747c4bb69b13403a8ae8151a089a7953978480faa0fe9857b089fd7cb