Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecf73a157b5d414a…

MALICIOUS

PDF

82.7 KB Created: 2021-09-02 08:57:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1c45794e84d2830c18100d57030bf046 SHA-1: f38c45318d28e79375e9d08d48315d83828a2aee SHA-256: ecf73a157b5d414a0b9ba536ca8b02a3f3a60e866fb3b1df09fb04034419b7c8
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external URIs and links to compromised CMS upload storage, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious, and the structure suggests it's designed to redirect users to potentially harmful content or for SEO manipulation. No scripts were extracted, but the primary attack pattern involves leveraging external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://retta-bg.com/userfiles/474852231.pdf In PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160ac94894a746---kibubitazusoreb.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607a632233af3---55269358898.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/galula.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/3526151c3b0d1a6fa4a0df302d4684ca/wexilelu.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/mewakolafolesuxavipo.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/jiguwexezuxeduroporif.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/8d90d76db43daa6e15570e0ddfb87958/77163857495.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/99855556510.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f26f34c7e5---kejavuxozejusogub.pdfIn PDF document text
    • http://ride.hu/images/uploads/files/ruguwuze.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607576fe7c07a---babiwove.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/mufamovopikazojufo.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d4e5b2dc43f---kumativurekazilof.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/bofijasen.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/90138500387.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/e948fb3df95c9ae46e6f5613eaa7611c/suxuruxofirutemepiv.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16109fa2309372---60580702373.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/87173315182.pdfIn PDF document text
    • http://dailitara.lt/bites/uploads/file/27462423304.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/bivubamutuwifixavamabe.pdfIn PDF document text
    • http://wghsclassof69reunion.com/clients/b/b3/b33699c65747f61a54cd06c2fab73d22/File/dabub.pdfIn PDF document text
    • https://semut73.com/contents//files/20259310100.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/h6ct99047ikr56cpi1p9ae0b9c/65382524853.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/h3vk2tsr5gpiv1bhv6uijb6b3i/tuwelimebazabobedujag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=only+connect+wall+templatePDF link annotation
    • 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_off0000ddfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f60e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60E 17600 bytes
SHA-256: 163af3ea3d7076940113589609c75c8c1e4ece6555a5fe476f8ae1c196102625
font_02_sfnt_off00012401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12401 10400 bytes
SHA-256: 147758427ab5e7143e1eb3865daf8fcd72b521503ed18da4fabbd8b1acd0c8d9

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