Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f0648529a6521b…

MALICIOUS

PDF

81.4 KB Created: 2021-09-12 22:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: ced40a4192c7e8e397169115965c34bf SHA-1: 3095640de537b3219457e2d28bae0f9fcbb3b150 SHA-256: a6f0648529a6521b6c351e524c022b5b5bc514cf60da6cb610bc26141dbc37c1
156 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 is identified as a link farm, with many links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://cructi.ru/uplcv?utm_term=the+charmed+ones+cast PDF link annotation
    • https://campfun.myhost888.com/upload/ckeditor/files/nizukibusipovu.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132fbea5bef0---1407031373.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f26c336a2e---70734585851.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/12684151429.pdfIn PDF document text
    • http://bachtungcompany.com/upload/files/kulakulatisabijefaroxegi.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/5f972ed1ccec6fe08b725b3bac4c091c/jegese.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/xilekazogibutuwisuzexezep.pdfIn PDF document text
    • http://normel.org/files/upload/file/8069604808.pdfIn PDF document text
    • http://cargologicru.com/sadm_files/kutewixu.pdfIn PDF document text
    • http://laptopcuhaiphong.vn/upload/files/96873574491.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/49715100529.pdfIn PDF document text
    • http://hkbroadwin.com/userfiles/89435838775.pdfIn PDF document text
    • http://rem-stroymont.ru/img/file/turepuwamogan.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/2169540315.pdfIn PDF document text
    • http://shesob.com/file/files/denexarakunovure.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/50902527350.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/50521415964.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/9017204319.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/20805332732.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/85351201550.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/zamajukoxisilulotatimexik.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/fafefonuvaguga.pdfIn PDF document text
    • https://digireg.it/upload/51894473675.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_off0000da1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f235.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF235 10460 bytes
SHA-256: 2bf41a671581531d5291b9b597d77af99ef93e6c9fdd5c82b36f530d1dd83448
font_02_sfnt_off000109ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109CA 17888 bytes
SHA-256: ffa9b8760651d552d738f8c222b36eb0632c1f737c7714341589528933895fd3