Malicious PDF — malware analysis report

Static analysis result for SHA-256 621843dd8eb51eeb…

MALICIOUS

PDF

69.9 KB Created: 2021-06-08 08:37:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: dd530a38975f55413357b59ef65f792d SHA-1: 11a1c3223b39325bbfb588b29018f23f9ecf5043 SHA-256: 621843dd8eb51eeb609022d561a83040f24324fac7b9c948aa15f09a22ae85e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan distribution attempt. It contains numerous links to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, appears to be a lure related to 'Imagenes de cerebros para colorear'. No scripts were extracted, but the PDF structure and URL patterns are indicative of a malicious campaign.

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://infrive.ru/uplcv?utm_term=imagenes+de+cerebros+para+colorear PDF link annotation
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096f1923d935---83707636915.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/a85a16220a94a30a92562edda6512252/113102437.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/25561626932.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be902a9e9a0---39052399175.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d96a3dfd24---60710291194.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bcbf688a5---95066023908.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/61b03a41464ae53c1360bfd7ae1f9235/limixabigij.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086203c9dae2---juxafuwugigulejotafa.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/hom92lufvhavj3qjhb4rlpsih2/58521605476.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf8104d064---runox.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160abdf7c10c8d---88638661582.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/mixalurikitugexokeduxug.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/5dc1d4faec75b1b6d96fa968fb3f7705/wifovu.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160762894d4c22---9862990477.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/a299ccde6ffe16af463b9b2853659da1/50628922760.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/2bme5lm5p3lp1t0ejrtng8hrd6/kikumoza.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_off0000d2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2ED 5472 bytes
SHA-256: e0149ee5bc2b6bb0635b061183b55f464e0d1f4ecc1f3c64d176493c805d2742
font_01_sfnt_off0000e564.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE564 10960 bytes
SHA-256: 5d432230ad48594f40e7944e9b4d1bfef8d528c8acfd4d1146ba220f0271c07e