Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca8a5fe6bd9fb326…

MALICIOUS

PDF

79.9 KB Created: 2021-09-18 06:26:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4f70bb786374fb5d991b81e380d733d0 SHA-1: 2504abbdf908a6250ae8a7258cc77032e06091a9 SHA-256: ca8a5fe6bd9fb3268594bf05aef736f95291b846adbf57a230797081a5423223
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. The document also features a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to obscure the true destination or host malicious content. The presence of embedded JavaScript and external links indicates a likely attempt to download additional payloads or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://smidgel.ru/uplcv?utm_term=can+you+get+safari+on+android
    • http://weingut-suppan.at/files/90601735491.pdf
    • https://quangtriasianwindow.com/uploads/image/files/fesinepejasi.pdf
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/161454d1c863fb---67447100704.pdf
    • http://shceping.com/upFile/photos/2021-9/file/9853143206.pdf
    • http://gavionescodeinsa.com/userfiles/86403350602.pdf
    • http://stellar.ru/ckfinder/userfiles/files/saximolepejefowow.pdf
    • http://patanamachine.com/imgUpload/files/kawewavu.pdf
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a21fc26246---53816302126.pdf
    • http://essiac.cz/UserFiles/file/razegagazuxepadidefal.pdf
    • https://allmassage.net/upload/file/20210918094529.pdf
    • http://jnejendomsdrift.dk/userfiles/file/30335083565.pdf
    • http://www.thaiboat.net/image/upload/File/92289205366.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/e302bedd0dbf1194766c41017124624f/70078742854.pdf
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/wuluvaporifun.pdf
    • https://hurghadalife.net/userfiles/files/kopesuzotewamoturub.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/bb5a6d1c2670950b87c80b897b392514/64553191465.pdf
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/8d4c7ea34a5e43b13e76905d1f8d374f/dekukulexar.pdf
    • http://skpizzasubs.com/uploads/files/satarenuz.pdf
    • https://edenestates.com/ckfinder/userfiles/files/57445273720.pdf
    • http://santiagoporter.com/js/ckfinder/core/connector/php/files/poziwuze.pdf
    • http://brukbet.com/user_images/file/winodotu.pdf
    • https://cli-kh.com/uploads/files/202109010557531570.pdf
    • http://stilistspb.online/public/files/uploads/files/rureromore.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144aa7e03ef3---taxebijegis.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_off0000d574.bin
15f0e681793a98d30c18cba3e339b974f4559454cee92fa9f6ff5929cfce402c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD574 17264 bytes
font_01_sfnt_off0001016f.bin
9647fb1f77a4a36d9581a1d088130dc0c0a7b9a73ced2f7661ef6897db6dfaea
pdf-font-stream PDF embedded font (sfnt) at offset 0x1016F 10728 bytes
font_02_sfnt_off00011a19.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A19 16792 bytes