Malicious PDF — malware analysis report

Static analysis result for SHA-256 0741a8a1f6658d82…

MALICIOUS

PDF

74.4 KB Created: 2021-06-07 17:53:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6e3ec78c037db5b09034b205b8650bba SHA-1: f24b93381d589b354efdad6e102741ef2d2da4c7 SHA-256: 0741a8a1f6658d82ac111e98b61ca5db1fe81e5dfa9e1d38194ee06bbaea21ba
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm designed for phishing or malware distribution. The heuristic 'ML_NYX_PDF_MALICIOUS' and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to a 'Net frog dissection worksheet answer key'.

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://wastran.ru/uplcv?utm_term=net+frog+dissection+worksheet+answer+key+pdf PDF link annotation
    • https://usssecuritate.ro/userfiles/file/34724849617.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/auvbhk0c2r8ndj0rundtuvise6/28143992754.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/3094632365.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/atihd3pbq4t26ccj253lf1in65/pakux.pdfIn PDF document text
    • http://antifftech.com/uploadfile/file/%5C/2021050322073788.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d430d74cb5---95274402323.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/68752106112.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a651f9419a6---bevuxasop.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609520480b9ca---merotosaseruvovonaja.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/83188973171.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0006ed68d---poluru.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/cc3a16468e6013ba707e1e8d77b6aa75/bajivuvuxu.pdfIn PDF document text
    • https://rebel-guitars.com/wp-content/plugins/super-forms/uploads/php/files/a7d7b4014096a9d1c09bf8730e367fbe/85063845413.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/0fb74ecfac05a62dc62cd8716629c61c/13203021485.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/nafepagibilatirogo.pdfIn PDF document text
    • https://seerupit.dk/assens/file/nifebuwevaxoj.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7eb0ae6a2---95037790487.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_off0000e55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE55D 5612 bytes
SHA-256: c4ed58da978e1c0f4447ea2f9e84a5edee435149e78d38aad9c8410f1ca679a3
font_01_sfnt_off0000f8a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8A7 10460 bytes
SHA-256: ef9f5d7a4dd7b0c5068ed497a98d2ee3701232157a1cb8bb8e66dbfed5d4808f