Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c27e52ed47bd157…

MALICIOUS

PDF

82.7 KB Created: 2021-09-18 11:08:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 921113c529b72e3644c0274414ca8f4b SHA-1: 42ed62318dc060788c7acb300ab13289a0a58e19 SHA-256: 4c27e52ed47bd1578d9a7ec98ffc3aee9a789cb2e4ead07823601578686c5cab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://101-games.ru/images/uploads/files/3040925199.pdf In PDF document text
    • https://zd-zeta.com/uploads/files/202109080244235362.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/gowofa.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/72923786751.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/3ac505464faec249eed29e3f191f32bb/zuminepupad.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/73792247389.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/20813751081.pdfIn PDF document text
    • http://maynenkhipuma.vn/quangbasanpham/app/webroot/upload/image/files/3506574060.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/98029955347.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb649063d---79781289601.pdfIn PDF document text
    • http://bluebiz.kr/userData/board/file/76432259017.pdfIn PDF document text
    • https://cosmopolitanhotelbg.com/uploads/wysiwyg/files/lesedutu.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/lobazejur.pdfIn PDF document text
    • https://autoroman-service.ro/imagini_ws/kepamexukiduxowewelol.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/pixubidu.pdfIn PDF document text
    • https://doktor-ara.com/userfiles/files/18853515149.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/kapufumebawoki.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/xaperisus.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/sikiwupuxusegosominiso.pdfIn PDF document text
    • https://coaching-jk-academic.com/ckfinder/userfiles/files/kaxanijodopuvipadi.pdfIn PDF document text
    • http://soloparamideco.com/js/new/fckeditor/userfiles/file/terase.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/79902116375.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/9qf5ree9dartrefhjlgkva99ut/57971623269.pdfIn PDF document text
    • https://standsimulator.com/ckfinder/userfiles/files/xukazokimirutanajoka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=social+media+marketing+step+by+step+pdfPDF 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_off0000dce3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F5 17520 bytes
SHA-256: bf106e0cdc7474a0880d2b5e9d6fdebe1d644890b2d3b66a626ae8ee4ff43316
font_02_sfnt_off0001222b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222B 11384 bytes
SHA-256: 8ded027faaa404d1ddd36783dac0e8f42f4f601f14251c3a5ec11c25474d961f