Malicious PDF — malware analysis report

Static analysis result for SHA-256 8634c9147fce6c5e…

MALICIOUS

PDF

75.0 KB Created: 2021-06-24 04:36:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 0fadc3208ababe942c9776b7c749c81d SHA-1: 528b3125889bdb09d16c0ffc5ddc0e71ead74e0b SHA-256: 8634c9147fce6c5e60ac3b12eadec5a5b226ddfce68730abf4db51de8adba708
156 Risk Score

Malware Insights

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

The PDF contains multiple links to external websites, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to a crossword clue, likely to entice users to click on the embedded malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://nomylo.ru/uplcv?utm_term=math+term+crossword+clue PDF link annotation
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f96046d16f---51685756232.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/afbc1c168c71e84ab70ddb1b3a56d33a/goxanerupejuleromese.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/b18c07e5154bddc6cac124c81c466e8b/10362322835.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16089c3fd9850a---pipen.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/gipududewujuk.pdfIn PDF document text
    • http://akinmedical.com/uploads/file/riwivaratesuwubigo.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609881bbe91b2---22930583490.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5f2fd9473---ponulirilesilazokejanitas.pdfIn PDF document text
    • http://lateonsettay-sachs.org/userfiles/file/69805744810.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca9e398d35---mutawokirojukibaser.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/4a2bbbda0f088dc6ab1463ef1cc2fad6/33967898942.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5f5bb6ce6---85684771080.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/46265782704.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/441048610b39702c5270c04b38694c5d/givimuzukezajel.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/6a6e9a3b22a2a7e2c0e8d423b738308e/43919016652.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/04f133fcf751efe788f370c5984aa389/wizitugowafomumukerod.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04b7cc8bbc---90360987550.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_off0000e836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE836 5276 bytes
SHA-256: 6a8b7863a803d576c759d08038894f0e69b85d36c55add9533160992e56d0aa9
font_01_sfnt_off0000fa14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA14 10988 bytes
SHA-256: 81aa1ef9d9df9c8b70e5b0657a3383a78106d4c2547bdd175e3ed60c9079e7b5