Malicious PDF — malware analysis report

Static analysis result for SHA-256 e71a835aa305bd2f…

MALICIOUS

PDF

86.2 KB Created: 2021-10-06 21:27:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 5db4ab1be3f416c27a859c740bd405e9 SHA-1: 535c024c65904004eb7c8e4af71f62c920bb0358 SHA-256: e71a835aa305bd2fe761279bb511c431c3031ace3f0ea5e6f4650ef7af2a7cbf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript and a large number of external URIs, many of which point to compromised websites or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically phishing. The embedded JavaScript likely facilitates the redirection to these malicious sites, contributing to the overall phishing attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://blccy.com/userfiles/files/59628379509.pdf In PDF document text
    • https://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/wozidojitulawufewur.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/wemedekamuminebevi.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/jeterus.pdfIn PDF document text
    • http://essentielles-theater.de/UserFiles/File/17338080474.pdfIn PDF document text
    • https://www.shamshabaddiocese.org/files/js/ckfinder/userfiles/files/63877798546.pdfIn PDF document text
    • http://donovaly-ubytovanie-safran.sk/web/userfiles/file/54238934755.pdfIn PDF document text
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/94953286808.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/17037057637.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/fe26c614ff45fb8ee5abe6cfd8054a2d/telemumaturu.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614fe88b6fb13---44236158862.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/290302098446.pdfIn PDF document text
    • http://olapromos.com/ola/uploads/editorImagesfiles/lujetunolotalivevoja.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202109131138472611.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/xukenulovudeledem.pdfIn PDF document text
    • http://qataminational.com/uploaded_files/userfiles/files/85642830999.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/24570136754.pdfIn PDF document text
    • https://pielinks.com/UserFiles/file/56164792922.pdfIn PDF document text
    • https://thuaphatlaihanoi.net/uploads/files/46716581121.pdfIn PDF document text
    • https://demo.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/dideluf.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613762b51ecc7---67632814966.pdfIn PDF document text
    • http://potentialdesign.cn/userfiles/file/1631477914.pdfIn PDF document text
    • http://xinge168.com/uploads/files/20211001060930_424999.pdfIn PDF document text
    • http://labmansour.com/app/webroot/js/ckfinder/userfiles/files/wevuwogipekefi.pdfIn PDF document text
    • http://meteoratourismactivities.com/files/files/nevuxuxegixoguvo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=income+percentile+by+statePDF 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_off0000e7f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F2 10740 bytes
SHA-256: ea5476cef690bd253cf87eed66ea6bac29cb68c7f1fb04464169af3eebe0c55e
font_01_sfnt_off00010063.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10063 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11875 19296 bytes
SHA-256: 334bf3c5979d52d6879e90a82bbaaabf39bcd38cae0c5770229635b7f0ab8832