Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad68cbe2f93555a9…

MALICIOUS

PDF

75.8 KB Created: 2021-09-16 02:58:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9eb50719345014c0b6302ce9fad15a9d SHA-1: f8f356e6e1d229ed2e1924c723f66c1c36302bf4 SHA-256: ad68cbe2f93555a97fd1221a0457a5eea04dfa5ef3cf872ed4e5dcffc4b11430
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate the presence of external URIs and links pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO poisoning attempt. The document body is heavily obfuscated and contains no readable content, preventing further analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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.
  • 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://cructi.ru/uplcv?utm_term=the+best+men%27s+haircut+for+your+face+shape PDF link annotation
    • http://chukysovin.com/img-svc/files/60159096855.pdfIn PDF document text
    • http://freestyler.cz/img/file/kijos.pdfIn PDF document text
    • http://secondhandgraphics.com/usrfiles/file/zuzubagorifi.pdfIn PDF document text
    • http://dirpub.org/editor/ckfinder/userfiles/files/guson.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/6829313655.pdfIn PDF document text
    • http://bundoreh.com/fckeditor/files/file/4398695296.pdfIn PDF document text
    • http://shanghaiqingchen.com/upload/files/tifulujatazutoruwe.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/44359631519.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/84a91vg0ema83bod1ral582brf/81770862178.pdfIn PDF document text
    • https://eurotig.ro/file/gotufutexixifam.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/18046427432.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/2101140484613f40333012b.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/bajebazutilovatafusasi.pdfIn PDF document text
    • https://almentispharma.com/ckfinder/userfiles/files/67007380709.pdfIn PDF document text
    • http://meijialx.com/ckfinder/userfiles/files/nevaluzaripijif.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/jemafep.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/7b2b32daa20fe0e08f8f7619cfa9828b/63589039053.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/lomax.pdfIn PDF document text
    • http://onishi-kyosendo.jp/archive/mepodinibapop.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/51631840280.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/6b7910c2c0d8e392156f2b56da9eec67/wonexilikani.pdfIn PDF document text
    • http://studiorapizza.it/userfiles/files/bevibaw.pdfIn PDF document text
    • http://sun-green.be/ckfinder/userfiles/files/34662632560.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/f801d1eb545a340e24dd6d005f8b2423/71076505075.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161362e1e4b54f---3401399052.pdfIn PDF document text
    • 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_off0000c48d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC48D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA4 11052 bytes
SHA-256: 6741445bb01cce06fd42def7af823c07bd9ccdee589f7015e3690deb3f3a1fd3
font_02_sfnt_off0000f611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF611 16748 bytes
SHA-256: 8076f57a7ec3177b1a320abab6493072d65f421a794a981068df791fb3292b07