Malicious PDF — malware analysis report

Static analysis result for SHA-256 19c431b2e0e5cb2e…

MALICIOUS

PDF

84.3 KB Created: 2021-09-10 15:44:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 390d19790c49459a9d306944474b8f9c SHA-1: 3457fe9d35c8c5b886519c3338843e974491c2c5 SHA-256: 19c431b2e0e5cb2ee8d40dde441f4ff0a41f0feb9d4e731ac218935268a69b9c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a link farm with numerous external URLs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a high volume of links to distinct, potentially disposable hosts, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, but the overall structure points to a malicious document designed to lure users to external sites.

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://charming-dc.com/uploads/files/202109100711324326.pdf In PDF document text
    • http://sethhukumchandschool.com/userfiles/file/71562539502.pdfIn PDF document text
    • https://cheesykeju.com/contents/files/26882383629.pdfIn PDF document text
    • http://imreelectric.sk/uploads/file/78584357018.pdfIn PDF document text
    • http://njxinbell.com/upload/files/81181327018.pdfIn PDF document text
    • http://prospekt-rostov.ru/ckfinder/userfiles/files/62317634307.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/7fbf8f0aff24bd929b53129d60e7cbff/75427057799.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/pumoxuguk.pdfIn PDF document text
    • http://geteffective.biz/uploadfiles/file/reduwesaja.pdfIn PDF document text
    • http://meubelenindex.nl/images/uploads/vukupabitomiwunurapaje.pdfIn PDF document text
    • http://shardamedicalstore.com/singhania/downloads/file/53721607697.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/pozosusaf.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/gisuxa.pdfIn PDF document text
    • http://idealthailand.com/file_media/file_image/file/71451109782.pdfIn PDF document text
    • https://idroilektriki.gr/files/file/71084682886.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613410de2646c---12491617706.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/joxebuwazabujixoxib.pdfIn PDF document text
    • http://swvocal.com/data/se2/file/57583263997.pdfIn PDF document text
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/xewifewijoku.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/zevapuwuxajoxu.pdfIn PDF document text
    • https://www.tratedu.net/ssss2018/assets/143ad273/ckfinder/core/connector/php/upload/userfiles/files/57e01be5a6979bc685d1abaf9b53db44.pdfIn PDF document text
    • https://ever-progress.dacola.com/upload/files/lesozalos.pdfIn PDF document text
    • http://btfa.tw/upload/files/88874537107.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/tivogatabuxukasatuvupav.pdfIn PDF document text
    • http://vencedor.coop/images/admin/file/nidavozepivikiretogur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=betta+fish+live+wallpaper+mod+apkPDF 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_off0000dbca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCA 10956 bytes
SHA-256: ee7690e187563c277d62c05b726284823b9766341fe0736a58cfa93966d061b4
font_01_sfnt_off0000f53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53D 20752 bytes
SHA-256: ac5b2984732ae4b680d377e7ef5e44fd635ae7e882b0dec8e249907e9fb97953
font_02_sfnt_off00012b2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B2B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1