Malicious PDF — malware analysis report

Static analysis result for SHA-256 16c6e8acf1b2d901…

MALICIOUS

PDF

84.0 KB Created: 2021-06-28 23:03:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 54a61614634b77499ffdf72321a55244 SHA-1: cb65b06a9bc14aeaf58b811fb6653dfe7196f123 SHA-256: 16c6e8acf1b2d901f15a698ea3da1eba48b3e4dc87dd0c0fe05ff8a1ec1c296b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://briljant-maleri.se/UserFiles/files/66497246372.pdf
    • https://bangprice.com/bangprice.com/beta/cms_image/file/degiwiweziwu.pdf
    • http://quatanggiabao.com/images/uploads/files/vozuza.pdf
    • https://lesartsdansmonjardin.com/userfiles/file/20210522173442.pdf
    • http://piau-po21inn.com/CKEdit/upload/files/52856963943.pdf
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7cacb9a27---98960905883.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/n4m6gaect5se555cqfn4qktjc5/81467062080.pdf
    • http://poorclarescork.ie/images/jilazunojudixuvu.pdf
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/mafabevedezo.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160965735bfb66---29421050026.pdf
    • http://normel.org/files/upload/file/ripaveger.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bcd2fe1b012---78304017155.pdf
    • http://nuraski.pl/wsg/userfiles/22380881930.pdf
    • https://nnt52.ru/userfiles/file/66414022354.pdf
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/90373777795.pdf
    • https://angkortaxiservice.com/userfiles/file/tufovobepixuporijojutob.pdf
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/pavumuvani.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f47deda93a---88618450456.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/487636b4aa9f6e07be0730c1646e9428/65737133636.pdf
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/a341101f940c9955027771a43bfa8b3f/todirimulatexezuruzofi.pdf
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5cd5431ae---48714823439.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a099cd7b9d8---11996879158.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=text+to+speech+chinese+accent
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6dd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DD 16792 bytes
font_01_sfnt_off0000fef4.bin
785fe7cabcac9554c1ffe5bbb4ba2781d52332daeb75fc22d4d100b8cb90624f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF4 10392 bytes
font_02_sfnt_off00011681.bin
b9565dc0ef31584857c5e648d37b6a9ac08dc2a17fbb84b87486799a611a34fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x11681 17264 bytes