Malicious PDF — malware analysis report

Static analysis result for SHA-256 63a6a2caaf85b524…

MALICIOUS

PDF

69.8 KB Created: 2021-09-16 23:59:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a310170d22d03a93112797958d31b24f SHA-1: 53e88d731c102105d82a2392484357294f18da4b SHA-256: 63a6a2caaf85b52466ba917f8ef49f2282a9449cdaf4da9076f533474fd9f79e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and it contains numerous embedded URLs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm on disposable hosting, suggesting an attempt to obscure the true malicious destination. While no scripts were explicitly extracted, the presence of embedded URIs and the overall structure point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://onyx-innovations.com/assets/ckfinder/userfiles/files/75230197981.pdf In PDF document text
    • http://ccforum.kr/uploads/file/1630889818.pdfIn PDF document text
    • http://marathon-gexin.com/Uploadfiles/files/puzezisatumezulodo.pdfIn PDF document text
    • https://bepxuyenviet.com/upload/files/27194590493.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/46097073119.pdfIn PDF document text
    • http://cokhilegia.com/upload/files/78014844190.pdfIn PDF document text
    • http://factorycontrolprojects.com/userfiles/file/94757440306.pdfIn PDF document text
    • https://rcot.org/userfiles/file/44454055611.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/89314159399.pdfIn PDF document text
    • http://vikingpaint.com/user_file/file/8014175797.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/14920851634.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/5cadf16d30fb60a7bec8ca108ce366b5/fuxefojovodek.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/11316115429.pdfIn PDF document text
    • http://dzstock.com/Upfiles/file/gilowarepevomukevipa.pdfIn PDF document text
    • http://chromowane.com/userfiles/file/sulamarimefamot.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/4dab80c9bf0dc477541379058b0a33da/7258176084.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/jifoziki.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8a011de0e---mekitovixaj.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/gilezul.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/48802557508.pdfIn PDF document text
    • https://ozmutludokum.com/userfiles/file/83998934052.pdfIn PDF document text
    • https://wyslijpaczki.pl/app/webroot/files/userfiles/file/47765051645.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109080932489696.pdfIn PDF document text
    • https://sergiomauri.com/images/file/direjufipabedogusoromoguk.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/vomagojijizosofepo.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/worekodukitaven.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/72874609502.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=gta+3+4+5PDF 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_off0000b814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB814 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD026 14368 bytes
SHA-256: 4f6227991ddaed53777dfafd53d893a47c04526038345ee9ff60ee53b715826f
font_02_sfnt_off0000f3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F9 9764 bytes
SHA-256: 0502facf069e70ce65f8a4ff34608fa527f6acaaa9d0304505126f5f37b8d1a4