Malicious PDF — malware analysis report

Static analysis result for SHA-256 4155e1e9b58c4a1b…

MALICIOUS

PDF

86.8 KB Created: 2021-08-27 18:54:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8361db33cde50e4cfef2bbaf8a4f015a SHA-1: 5628babc8790677d8f519296237ba134846c58fc SHA-256: 4155e1e9b58c4a1b8f13a52b624842b5ac97a7355953e4787663df5b4488fc14
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external links, many pointing to compromised WordPress sites and using URL parameters suggestive of phishing lures. The presence of embedded URLs and the nature of the heuristics suggest the document is designed to redirect users to malicious content, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://huntic.ru/uplcv?utm_term=6+year+old+tonsillectomy+recovery PDF link annotation
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160abd1977ca48---wotanovowapewabe.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/89151593590.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/9852dd5e45f447f7a6b98207c64407b0/gagusatifok.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea831b6783---dogugemenimav.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6878406672---10405257264.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a9933234702---53636469535.pdfIn PDF document text
    • https://haisanquangninh.org/data/dulieu/files/jupibusowisa.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a853d161a9b---34104781287.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/morizubesakibezaf.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb11857054---32783203518.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/95863392445.pdfIn PDF document text
    • https://tigercabinetry.com/wp-content/plugins/super-forms/uploads/php/files/93e900cbeddf8d2a62c33e4d5dd2c4a7/32023787223.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/sifofinimuzanugu.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/17308185774.pdfIn PDF document text
    • http://jr.ac.th/ckfinder/userfiles/files/nipele.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/59257355699.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/ruvigudafa.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/16362820924.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fd98cf478---tikegafa.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160813b94e83e6---17056171250.pdfIn PDF document text
    • http://chizclean.ru/files/fck/file/gunegosemixozu.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1609d811e9fd5b---26328298179.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160851ad5872c1---kixafota.pdfIn PDF document text
    • https://nadinerogger.ch/userfiles/files/dajezefoxutukilax.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/945hcp2eldf7rnrjidr5dm95h5/pipetilodasamawanaja.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/tubarit.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_off0000efeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEB 10780 bytes
SHA-256: 8866480cd16f2527767025d02fc27a3377f656bae4949fedbc94a5c6ef07e9b8
font_01_sfnt_off000108c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C3 17256 bytes
SHA-256: 8c6d3783f5d67048ea128f47e753bd39371317b375f65b4229ae3b81a5ed9321
font_02_sfnt_off00013556.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13556 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1