Malicious PDF — malware analysis report

Static analysis result for SHA-256 e87acf20963a4da2…

MALICIOUS

PDF

75.1 KB Created: 2021-09-13 06:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 45edb11fd0dfeec7eea05cb351be927e SHA-1: 75983727229e3d971ff0fac3db3ec8e1e8e7c605 SHA-256: e87acf20963a4da2cf59990305c4e569ac2bd3d945f17c39609061913dfd2378
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and external URIs. The PDF contains numerous links to disposable domains, suggesting a link farm used for phishing or distributing further malicious content. The embedded JavaScript likely facilitates the redirection to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://synerhu.ru/uplcv?utm_term=a+line+graph+does+not PDF link annotation
    • http://graciaindoutama.com/kingkong/userfiles/files/25304989943.pdfIn PDF document text
    • http://benetalent.com/upload/files/34593481996.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/61116629824.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/5575459820.pdfIn PDF document text
    • https://clubberia.com/js/ckfinder/userfiles/files/9255007138.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/gigibevobebekulam.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/sibusupekomok.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/goredepamaduvixadokib.pdfIn PDF document text
    • http://studiospazioambiente.it/userfiles/files/66769041136.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8b31867c4---zagasevabuxenulomanuluzep.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/7vq8t0meaa89u4edvfc5dbfo32/tepatavosepopamuzibam.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/19756341236.pdfIn PDF document text
    • http://vikingpaint.com/user_file/file/fawesigudixelevede.pdfIn PDF document text
    • http://schule.havonix.com/ckfinder/userfiles/files/7470747679.pdfIn PDF document text
    • http://krupongs.com/images/file/24196337557.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/kutox.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/sitaliwikusitawobulumo.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/vusef.pdfIn PDF document text
    • https://madame-tina.com/ckfinder/userfiles/files/65711429931.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/xasudupapapanujowuxiteta.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/42582969755.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_off0000c35d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC35D 16940 bytes
SHA-256: 6ee67c9821860da553c3df85685d6d2b1920d8efbd4327980a5de6131d72b82b
font_01_sfnt_off0000eeeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEB 10652 bytes
SHA-256: 8ce6d1483ce6112543acee36237b8b0b223eff78df6ff035a8be342ecbbfef81
font_02_sfnt_off00010701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10701 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1