Malicious PDF — malware analysis report

Static analysis result for SHA-256 b90c4639c5d51814…

MALICIOUS

PDF

85.6 KB Created: 2021-09-06 00:37:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 977bf5447dfaadbde3deb4bec52c9cc6 SHA-1: c854ccab19ccc2ca700cb0875bde6e23a2bbca0f SHA-256: b90c4639c5d5181464be75b847f5c756020dbdd3c73a4358273fe16f88001098
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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 disposable hosting domains. The embedded URLs suggest an attempt to distribute phishing content or further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://medvor.ru/uplcv?utm_term=rumi+the+art+of+loving+pdf PDF link annotation
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16072ca48d3896---sidemidatamikixif.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/18892525017.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f044dc04ca---81958547642.pdfIn PDF document text
    • https://rasorestefano.it/file/23018704186.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/1ckkmthl6h72theufklmcod2m5/7897166399.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/savenilumenetiliponij.pdfIn PDF document text
    • http://tartak-monis.pl/tartak/images/file/96001453440.pdfIn PDF document text
    • http://indigobaby.eu/upload/files/50459373633.pdfIn PDF document text
    • http://williamshudson.org/clients/3/35/35bf74ce48b5c120232fd40fb4fe3e45/File/42452141742.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7610963f5b9dc64e408ed785ef239982/37387979238.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ee8b267b420---72955784494.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/kefimedajedu.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16085e3326378a---bewejexututekot.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/8cae1f4af2fba9eb7844b531d4c3cb9c/jufizekir.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/sajijivegusunugama.pdfIn PDF document text
    • https://kisikana.hr/userfiles/file/xatimotiw.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160848c63d6224---65675409912.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/8367e74f68f82276adad3cadd402f6b9/wadipemu.pdfIn PDF document text
    • http://air-ned.com/uploads/files/80975143461.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/xejelapexolalazewiz.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/bisidodimisopijom.pdfIn PDF document text
    • https://vegan-eshop.cz/data/file/marudugilola.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/tarumogodojir.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/nibiruratoxevuwixewigav.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/jinid.pdfIn PDF document text
    • http://kredoteka.ru/uploads/file/18704769345.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_off0000eba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B8 16980 bytes
SHA-256: 86eafdcb1a5bdbf1f85da13aa8415abf9e712f87da3ce79b457b8787f4a1cb4f
font_02_sfnt_off00012f75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F75 10988 bytes
SHA-256: 7d24bf846d1ff6fea10151ba6602e50c81039e00ef20e005a5e5b6ffc8a30d23