Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f3370716f5dbaf…

MALICIOUS

PDF

85.3 KB Created: 2021-09-16 09:59:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e42acf0e54efca8bcbb6b8b8e3f4b385 SHA-1: d46813b97b4a53c2ee6b44e34b6090814e66cf5c SHA-256: 21f3370716f5dbafe671057d2823655841418c824caaf34232597bdf6f144f58
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many hosted on compromised or disposable domains, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and the nature of the heuristics indicate the document's primary purpose is to lead users to external content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://crysiq.ru/uplcv?utm_term=zen+launcher+apk PDF link annotation
    • https://laundrybyconrads.com/nbloom/fckuploads/file/71551120195.pdfIn PDF document text
    • http://envisystem.com/upload/userfile/files/4321702091.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc61aa366f---7718343792.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/95832051690.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/5aed76000659ab49d645a12014f5ae62/74194677549.pdfIn PDF document text
    • http://razzledazzleevents.in/userfiles/file/24604016167.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/xiwevidegapib.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/33178926374.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/89397283781.pdfIn PDF document text
    • http://normel.org/files/upload/file/52301209898.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16140d4c3e8e6f---zalekulagudikoxuki.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/73275605490.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/powegubowosanevanis.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/27338269210.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/92904476815.pdfIn PDF document text
    • http://hutbephottaihaiphong24h.com/upload/files/88644396774.pdfIn PDF document text
    • https://presentkompaniet.com/img/content/file/90890023175.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba0abe4c25---sufigerefo.pdfIn PDF document text
    • https://olgunbey.com/upload/ckfinder/files/kekopimu.pdfIn PDF document text
    • http://decaldankinh.net/upload/files/jarojujuxagerulovunetalu.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/xufimudesesixidenad.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/juduliguzavuju.pdfIn PDF document text
    • http://karthikeyanjayaram.com/userfiles/file/debolanopila.pdfIn PDF document text
    • http://3colorjazz.com/fckeditor/userfiles/image/94122549083.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/dopituxesa.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/99200082095.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_off0000e739.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE739 10148 bytes
SHA-256: a948d5429e422a72ca48dcfcd49257a463eb3a04df4ed33dc2bb33a825b9680b
font_01_sfnt_off0000fdcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDCD 19352 bytes
SHA-256: 1cb0f07223802a088a276e6336e828414c3ff021ce0968fa538b5d1fb3164095
font_02_sfnt_off0001300c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1300C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1