Malicious PDF — malware analysis report

Static analysis result for SHA-256 e66a4bdf86b96f50…

MALICIOUS

PDF

88.9 KB Created: 2021-09-03 07:19:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c98e80fdaa0bf43164b6535b2e05f68f SHA-1: 12c4ff0411a3dbafc5d56ebcfd6929ba00f8dcb9 SHA-256: e66a4bdf86b96f509140e8b23ff5eeab6d0ab8f2970cf2bf2c22852b96bb119e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The ML classifier and ClamAV both flagged this PDF as malicious. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other domains. These links likely lead to phishing pages or further malware downloads, aligning with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://stonepigments.com/userfiles/file/saxoteku.pdf In PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/64290475762.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b9941727762---dobizopuvixugajifitulu.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac100049fb3---26513476075.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/65975687333.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/gazedekezufo.pdfIn PDF document text
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/22310413149.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/petapugo.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086e1bfd50a2---mixolozoxogewam.pdfIn PDF document text
    • https://frigosztufi.ro/ckfinder/userfiles/files/64364376077.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/mezetulupoki.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/ad95ae09855371c8a685abb602153336/37152236357.pdfIn PDF document text
    • http://euroinstytut.pl/galeria/file/65492726030.pdfIn PDF document text
    • https://mosconi.net/userfiles/file/piver.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/rrdnlfhg75f7jc08sak4bl697s/79178207771.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16080e06049516---94910455786.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a677f75f34b---54324997223.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab975944c73---62608994504.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/90c027a05a20a3926b027fa09018291a/90692081942.pdfIn PDF document text
    • https://lamthong-marchph.com/piceditor/file/94371149266.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/74fbe5f200281de311196b25b1f4b3ff/69608404061.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609db20919953---gitenevovegurek.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/jsmrn8jbesl130bv3uejuhjmjs/gopifo.pdfIn PDF document text
    • http://sweetbasketsbyjackie.com/clients/864293/File/79914935646.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a3bf5ed0bf---fidabopes.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/28905849749.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=grandma+climbs+a+tree+poem+pdfPDF 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://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_off0000f68c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF68C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010ea3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA3 10960 bytes
SHA-256: c26288b475d9c7be52cea431c765447b10e4dcca02eb46839267038817b81b99
font_02_sfnt_off000127c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127C9 17816 bytes
SHA-256: 77aaf64353d1c90e9c8b44b76d0e4f2772f00c57ede81eecf8560b847d43a472