Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b7e52dc7cd4ebd7…

MALICIOUS

PDF

81.4 KB Created: 2021-09-24 09:36:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 733fd779644b5fc39beda7441b35be9a SHA-1: afd785293a8269021dda40baca920a0640ba184d SHA-256: 8b7e52dc7cd4ebd7159729ea8622b2ebf53c3251a9a0de270daa31409439f66f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to PDF files hosted on domains flagged as link farms or potentially compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://svazekobciorlice.cz/userfiles/file/6588984099.pdf In PDF document text
    • http://mackyz7automotive.com/js/upload/files/gotimosurukuzosakos.pdfIn PDF document text
    • https://nepaltrekkinginhimalaya.com/assets/userfiles/files/79340303092.pdfIn PDF document text
    • http://nhahanghienminh68.com/upload/files/76642570038.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/pufoxefuladabu.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/6f696b9d27bcfb09cc2f4d41f1566138/90830537288.pdfIn PDF document text
    • https://majubesar.net/contents/files/linobutivugadusoli.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210920022538.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/51b358ba5fea27942134e13dc1f881f6/rivawadugiga.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/rutupaxilaxokaru.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/disaninadivisuvatowa.pdfIn PDF document text
    • http://gelateriacool.it/userfiles/files/gufikogiwotebolazekuga.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/91376320876.pdfIn PDF document text
    • http://farmandari-sarvestan.ir/images/news/files/benigex.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4e1ad3e6e---gexesapuvuwogi.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/43525877241.pdfIn PDF document text
    • https://pu-sk.com/app/templates/js/ckfinder/userfiles/files/kuxobisugituvuda.pdfIn PDF document text
    • https://olivierdaulte.com/ckfinder/userfiles/files/63921156683.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/90b74b08a7dd7f1e535dfe1787eed12d/tufosuroxidesude.pdfIn PDF document text
    • https://soechi.com/userfiles/file/21029024690.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/gepuviguvilavo.pdfIn PDF document text
    • http://autoneza.cz/UserFiles/File/88773343963.pdfIn PDF document text
    • http://shinaval.ru/userfiles/file/ratoza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=pinterest+chrome+extension+androidPDF 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_off0000d9f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F2 17624 bytes
SHA-256: 221ec571f68c8a2c0a489108189ceaa069fe1bfa71e4402d2de85b41e9b31ec0
font_01_sfnt_off0001076a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1076A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F81 10692 bytes
SHA-256: 5ef38a075c8bdce78769aeb7fbe9d24f4cd3feadba7017e7efd952f40215bc42