Malicious PDF — malware analysis report

Static analysis result for SHA-256 656592ce6df64768…

MALICIOUS

PDF

79.7 KB Created: 2021-09-05 17:52:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ed69b465cb532c2cc5cc8978aa3278c1 SHA-1: 2e7c8536f472b29c30ad51397655857ede9ecf6d SHA-256: 656592ce6df647688443f192e8609cbd5b50606af3743deaf9f6fbfa15a9d7f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ketchas.ru/uplcv?utm_term=possessive+pronouns+exercises+pdf+beginners PDF link annotation
    • http://plncse.hu/php_data/file/35749882812.pdfIn PDF document text
    • http://studiotecnicopetrillo.eu/userfiles/files/75809524574.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/93866807629.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/6987927591.pdfIn PDF document text
    • http://nappsa.org/userfiles/file/28853212252.pdfIn PDF document text
    • https://nakshistudio.com/ckfinder/userfiles/files/26038701210.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/77a7435c9d731bd2bf0837bb73682c23/84191834037.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160719abe8e907---kunavop.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/detorogifuk.pdfIn PDF document text
    • http://www.prctech-th.com/ckfinder/userfiles/files/71104398339.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984a56dae34---tesef.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076939855633---befumegasivazemunozit.pdfIn PDF document text
    • https://netlandschool.cl/files/76226436974.pdfIn PDF document text
    • http://7tec.ru/userfiles/files/11799474165.pdfIn PDF document text
    • http://hy-concrete.ru/d/files/milizamitenedotezinagabuw.pdfIn PDF document text
    • http://conniecorsentino.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/raduzozo.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609b80ca5b489---3639606570.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160afa35ba90f2---14903568801.pdfIn PDF document text
    • http://mail-ex.net/userfiles/file/51053571668.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/39874817856.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/zutakijikaninovevit.pdfIn 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://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_off0000d417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD417 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2E 10900 bytes
SHA-256: fa83a334e21dd42e7dc9850672370c134e6f46a1105877d112b9e42fd52578b0
font_02_sfnt_off00010524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10524 17064 bytes
SHA-256: 399a19f9c18fecf736c22c2fbec6674bb7379ba99a687c1d1ad710b5e1b0afea