Malicious PDF — malware analysis report

Static analysis result for SHA-256 41e9fb9627412c2e…

MALICIOUS

PDF

92.6 KB Created: 2021-10-06 03:07:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a0e259ec4494f7a4c35cbb3b900b1654 SHA-1: 6fedfa2edfd4010bb4dc15ce2d266a919a13855a SHA-256: 41e9fb9627412c2e7a86f99ff9ce06ed93cb9f73b8cead82e4f26815565048c6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for redirecting users to malicious websites. The PDF also exhibits characteristics of a link farm, with numerous external URIs pointing to potentially disposable domains, suggesting an attempt to obscure the final malicious destination. The embedded JavaScript likely serves to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

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.dogwoodagility.nl/ckfinder/userfiles/files/4489977941.pdf In PDF document text
    • https://xehowo24h.com/images/ckeditor/files/58111354531.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/161596600363c3---80191640225.pdfIn PDF document text
    • http://artpolyclinic.com/file/files/bagof.pdfIn PDF document text
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/pudasa.pdfIn PDF document text
    • http://projecthouse.bg/uploads/CKfinder/files/7988864117.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/kizilefuxomimusifiporez.pdfIn PDF document text
    • http://varadimasszazs.hu/uploads/files/81518405459.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/wiwukizerakowopumideno.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/luxogibu.pdfIn PDF document text
    • http://townofwinslowin.com/flash/townofwinslowin.com/file/wababufo.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/komigolik.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/palozokafurosiwiwavofe.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/dizum.pdfIn PDF document text
    • https://bonvoyageindia.in/ckfinder/userfiles/files/54569361438.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/65178391975.pdfIn PDF document text
    • http://mavelikaradiocese.org/rapha/ckfinder/userfiles/files/96417699762.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16151767e39e8f---84864209768.pdfIn PDF document text
    • http://cybernet-ap.com/UserFiles/File/zanesowozeretetumorewo.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/fuzowurezoxoti.pdfIn PDF document text
    • http://kahounova.cz/userfiles/file/kipikuwagijewowaze.pdfIn PDF document text
    • https://dampinggame.com/calisma2/files/uploads/88355508774.pdfIn PDF document text
    • http://siamsnail.com/media/userfiles/files/bidimuvo.pdfIn PDF document text
    • https://gobelsprofil.com/upload/files/fabasinipavegejonigaduk.pdfIn PDF document text
    • http://ropesadventure.com/d/files/mefojifelojerokota.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/96380045770.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/vodudo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=florence+and+the+machine+concert+2021PDF 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_off0000fcdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDF 20400 bytes
SHA-256: 545314114348169036a39313beab3ed6c317347cbe14223b7b9f57d8e52a2a4c
font_01_sfnt_off00013230.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13230 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014a47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A47 10740 bytes
SHA-256: 94a8ca5a513abbecc0d21492debb437aca3da9f6e528ad58057940c5ad5b0236