Malicious PDF — malware analysis report

Static analysis result for SHA-256 98a490e6b6c217e9…

MALICIOUS

PDF

67.6 KB Created: 2021-10-02 17:26:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b5988e6e0e07e54f27abaec879153d48 SHA-1: 3e53212c020705f21f9496358c82b1fa23c42fb5 SHA-256: 98a490e6b6c217e9ce02770e6289572bb82fc5fc440a9bfd0b19d126ee7753aa
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. Multiple heuristics indicate the PDF is a link farm, with many URLs pointing to external sites, some hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://greenhere.cn/upload/ckimg/files/202109121044567135.pdf In PDF document text
    • https://aymsoft.us/aym_image/files/jotedesupoki.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/vuzupofig.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/xuzugapimog.pdfIn PDF document text
    • https://cpc-serbia.org/js/files/wanoj.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbfca9a0ea---lapawumukuwevozufutix.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/gefus.pdfIn PDF document text
    • http://szyldkj.com/luodan/images/userfiles/file/risex.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/91832887247.pdfIn PDF document text
    • https://congnghiepxd204.vn/upload/files/80562939566.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/d244d99c069b1cb9ab9866070199ad47/75696530543.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/hutg8ingindfoohqpitqsq67d0/sukuvapupezowupatotole.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/goniwodi.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/33649910955.pdfIn PDF document text
    • https://raiporjai.com/piceditor/file/44732335262.pdfIn PDF document text
    • https://barcelonacentromedico.es/files/galeria/files/12547181656.pdfIn PDF document text
    • https://alicantea.centralcms.cloud/galeria/files/70387987214.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/bawiponimupabulejagofov.pdfIn PDF document text
    • https://mkycc4.com/kycc4.com/userfiles/files/joxozafe.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b34d9404e4---19353076554.pdfIn PDF document text
    • http://captainkillmite.com/uploads/files/202109050835504593.pdfIn PDF document text
    • http://live-lessons.net/lcj/web/uploads/assets/file/51768765796.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=where+is+area+code+424+atPDF 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_off0000ac9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC9D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c4af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4AF 14496 bytes
SHA-256: 5a2c486e191940dcbf7c388ab381de64ccfaaf1e6db9f0a8635623b07fab27b8
font_02_sfnt_off0000e8f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F5 10508 bytes
SHA-256: 0f3089c90fdea91bb423db3f8eb7333d05f2710846207ff90cdc245d5dcfe0cf