Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c4e6e4049c1119e…

MALICIOUS

PDF

72.0 KB Created: 2021-09-08 15:45:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 5cd9fa3789612db3d089496f5f836e87 SHA-1: 04408cf4b8f85db713d8b710f3e78ba821d2cbf4 SHA-256: 4c4e6e4049c1119e7285a8ea98a2ae2dc0221df77101a2563f8590ae9982899a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code or redirecting users. Several heuristics indicate the document is part of a link farm, with many external URIs pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://naszymsladem.pl/upload/file/57914094912.pdf In PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/8e05d17317498cd7f924cfd81455ab79/74047149253.pdfIn PDF document text
    • http://indemo.pl/Image/files/13829983978.pdfIn PDF document text
    • http://vipacademy.org/userfiles/file/24139856268.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/48732982029.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/4902950837.pdfIn PDF document text
    • http://geriatriccarenewjersey.com/userfiles/files/fexobuguz.pdfIn PDF document text
    • http://okgwa.net/50/files1/file/wexesosilolekanopubuzo.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/63779047384.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/065d00c1c5f1f5c918c85b67ae18ff6d/bixekinalakuwomagom.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/xakinikum.pdfIn PDF document text
    • https://quatcongnghieput.com/uploads/files/97041167202.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c50914822---52996464913.pdfIn PDF document text
    • http://sin-hua.org/userfiles/43351360699.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/42690311831.pdfIn PDF document text
    • https://www.elshandmadedesign.nl/ckfinder/userfiles/files/7450404267.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109071844331546.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/sedogowiximaw.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/37814574009.pdfIn PDF document text
    • https://mashtalkandil.com/userfiles/file/66885787708.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/65687207562.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/83261426861.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=hydroponics+information+in+marathi+pdfPDF 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_off0000b56b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB56B 10812 bytes
SHA-256: f65ea7bbc9aeb18a43fc5f2918b1090fd73a877e618652ea5d98bf36dbdfb0f2
font_01_sfnt_off0000ce1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e62e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE62E 17124 bytes
SHA-256: e704b889870612c231d82b6357293b9bcdba8f0d0f3bfa67cbcc45551e44bfb9