Malicious PDF — malware analysis report

Static analysis result for SHA-256 40e5cbc8d21b47b7…

MALICIOUS

PDF

93.5 KB Created: 2021-08-09 07:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9831693ae65f94527ae0fefbdf6bb33 SHA-1: c98d818e45eae1611ec9ea15f517d84b210c8e57 SHA-256: 40e5cbc8d21b47b714f94dc5b8e295a12a9f7c1966d84017f04346918d7bb7a8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing multiple links to external websites, many of which are hosted on compromised CMS uploads or disposable hosting, indicating a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware delivery attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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
  • 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 http://adamshs-pdx.com/clients/d/d3/d3c120c733f7363e2cdaef2cff5f3687/File/71759457724.pdf
    • http://www.uc-kushiro.net/images/library//File/jifonojupulamibosifebi.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/20ebcb538a6d3c58fb9ca9dff9eb29c7/bizivixibesut.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160cb81e30eb53---96984079853.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ae6cad565---wowugunupidu.pdf
    • http://isystem.hu/userfiles/file/bikij.pdf
    • http://lubrifianti-auto.ro/files/file/15356128123.pdf
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d950126ed7---45983797508.pdf
    • http://accessiblevehicleservices.com/userfiles/file/petemunafopabupo.pdf
    • http://www.thaiboat.net/image/upload/File/bikoraloj.pdf
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/161044d123a45f---domozewifukapadogekubixu.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/0adec248d1e42f5fd37678296f0d76a8/95786852547.pdf
    • http://www.smartlandgroup.com//ckfinder/userfiles/files/50259336180.pdf
    • http://4bx.pl/public/file/51558517572.pdf
    • http://wardwrightself.com/clients/863644/File/65407299743.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/rj8uhosucprjcnmn3pl238m982/vabexaponezabevajagojifu.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb2f31f194---22457059497.pdf
    • http://besttailor.info/ckfinder/userfiles/files/81352918409.pdf
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607516219ccfb---dapurepikitunun.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/sri4h1of68o53ke2f83c1t4oru/lagazuxuwa.pdf
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/zulatexolakezuligapopano.pdf
    • https://alcoquimicos.com/ckfinder/userfiles/files/80741663113.pdf
    • https://bepxuyenviet.com/upload/files/kozasat.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=performance+appraisal+form+template+pdf
    • 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_off000108f4.bin
59bf5301b596add9ab5cb8368f703f268b9d9aa03b43d385c3c3ed86cdd2c2a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x108F4 16836 bytes
font_01_sfnt_off000134ce.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134CE 16792 bytes
font_02_sfnt_off00014ce5.bin
9a41b608ac8eb8b5c248579f1032428fb0280561b332a3633b0377665e95e3b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14CE5 10780 bytes