Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c386dddd57a62a3…

MALICIOUS

PDF

78.2 KB Created: 2021-09-13 16:12:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: de69bffcb26088b322a33a912175d773 SHA-1: eb947b829c2f4a8d674cd577692044051ad60616 SHA-256: 7c386dddd57a62a3173545b69db50f01000c62c05661449d48cdaaf316e35c4c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with a critical detection score. It contains embedded JavaScript and numerous external URIs, many of which point to a link farm hosted on disposable domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using multiple distinct hosts with a single link each, suggesting an attempt to obscure the true destination or evade detection. The embedded JavaScript likely facilitates the redirection to these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16138c45942e6f---95913581609.pdf In PDF document text
    • https://i-chat.tw/js/ckfinder/userfiles/files/89184362896.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/wemolirevaxisutigasekul.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/lowefujafebobamovag.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/gifevujirebowagovak.pdfIn PDF document text
    • http://mail-business.ru/uploads/file/22829088499.pdfIn PDF document text
    • https://www.bramfordgc.co.uk/ckfinder/userfiles/files/lumomelanofopolewu.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/28783460847.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/8522963078.pdfIn PDF document text
    • http://area100impianti.it/userfiles/files/teguvokep.pdfIn PDF document text
    • http://abpjse.news-read.com/upload/files/49129354791.pdfIn PDF document text
    • http://www.beautyvogue.ch/Files/file/petajagumufegoridujalizis.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/muxemorikipepesupu.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/66659636503.pdfIn PDF document text
    • http://tagsu.com/attachments/fckattachments/file/51574856265.pdfIn PDF document text
    • https://stl-log.com/htdocs/cljr/data/files/35565493297.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/vatunogaw.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/82414907027.pdfIn PDF document text
    • https://southernwashpros.com/nbloom/fckuploads/file/776785941.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/pusilarasikusado.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/sodikebuxipafuv.pdfIn PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/50049357292.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/71385275654.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/falizinifekusiwu.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/vovurabegojowepenedu.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/jisefilorivirupabopawu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=aloha+oe+ukulele+pdfPDF 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_off0000ca68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e27f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27F 10204 bytes
SHA-256: 00436ab5e8761813294efb25e8b574f06aa473567933230f2b20a6d6076c359a
font_02_sfnt_off0000f97f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97F 19004 bytes
SHA-256: 216b29092f3a02a70653a0ba967c960e124663b2f79cba61c2ca2a3c7525b61e