Malicious PDF — malware analysis report

Static analysis result for SHA-256 51e9aa460d742818…

MALICIOUS

PDF

83.4 KB Created: 2021-09-17 11:54:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 801cee578fb515c7ab3f7b59b97ade27 SHA-1: 4c204a0c29d3b6e71cabb1768bf1e8812cab0f3c SHA-256: 51e9aa460d7428185d982f47463e17e8d734c004424c008eb375a24196c55879
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to PDF files on various domains, indicating a link farm. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirms this behavior. ClamAV and ML classifiers also flagged the sample as malicious, specifically as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://icon-studios.com/userfiles/file/60176189840.pdf
    • http://cableesmaltado.com/d/files/widemaxigaxoxixu.pdf
    • http://cn-daomeng.com/upload/userfiles/files/731c0d259b2dd814205c611c5b66f059.pdf
    • http://pattarasawat.com/ckfinder/userfiles/files/7784038504.pdf
    • http://xycrusher.com/d/files/dakamafolupunatuzonuxog.pdf
    • https://ourcampuswindow.com/ckfinder/userfiles/files/14845069030.pdf
    • http://www.supair-lux.hu/ckfinder/userfiles/files/gizumutadigafukuxona.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c03aa8724f---tukabunimanupigotamagibe.pdf
    • https://pemaboutiquehotel.com/assets/userfiles/files/gabojilirogate.pdf
    • http://abwmercury.com/uploads/files/94810805008.pdf
    • http://hatowo.com/app/webroot/uploads/files/2183697572.pdf
    • https://www.prshots.com/ckfinder/userfiles/files/jubelogorepovowodumov.pdf
    • http://zaiger.ru/img/file/jadomegepejamegimamoviba.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613432c6d3d81---kufimanepo.pdf
    • http://malerbetrieb-malanders.de/Webseite/pics/fotos/1/file/90953361348.pdf
    • http://connectcontrol.net/files/userfiles/files/sarijusegoni.pdf
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/zosakava.pdf
    • http://educasters.co/ckfinder/userfiles/files/wedetofexedanutemasazek.pdf
    • http://vaynhe.com/upload/files/37207132030.pdf
    • http://morebricks.com/ckfinder/userfiles/files/wikalojutidavakuku.pdf
    • https://turismo-galicia.es/ckfinder/userfiles/files/36768899840.pdf
    • http://xyr59.com/filespath/files/20210916071913.pdf
    • http://obkladacstvikolar.com/content/8842078691.pdf
    • http://tucsokszekszard.hu/images/news/file/31169360903.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=my+hero+academia+movie+english
    • 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_off0000d4f0.bin
327c286d4e8d23bd0be3f35887cdf0dd3a5f7f7662cfe7d4b90a7672798aabd9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4F0 22260 bytes
font_01_sfnt_off00010ede.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EDE 16792 bytes
font_02_sfnt_off000126f5.bin
ffcb00f5688cfdf1497547e13ab9853460891e55c7f266a5cd8d12f461d14dd2
pdf-font-stream PDF embedded font (sfnt) at offset 0x126F5 10892 bytes