Malicious PDF — malware analysis report

Static analysis result for SHA-256 f565816871aaf124…

MALICIOUS

PDF

88.5 KB Created: 2021-09-19 22:00:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ffb0ad2300f7033b8ab04924659a7a2a SHA-1: 021f3fce8f28d63a767ef435f722f94cdfcc7d8c SHA-256: f565816871aaf124a08c74935bf3068f73a2b21b785c85d01f049c23dd8567ea
156 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it is a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or to serve a second-stage payload. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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 http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/dazute.pdf
    • https://hunghiephuylog.com/upload/files/fekobamater.pdf
    • https://konzolstudio.ro/uploaded_files/file/vawogotuganalesubadonise.pdf
    • http://www.heksan.com.pl/file/laforob.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/a7422ecc0d078a4dce51bed406850891/64990569710.pdf
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/66856758352.pdf
    • http://tiyuchangdi.com/upload_files/files/20210913_080449.pdf
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a11014fe56---44403298605.pdf
    • https://iqrainternationalschool.org/_assets/files/pedorakazebuz.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16144fac702f1e---sujufazuwanoma.pdf
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/3806836128.pdf
    • http://silky.ae/images/bulk_images/files/61976669255.pdf
    • http://bud-med.eu/userfiles/file/nukafugenifumu.pdf
    • https://langumeistras.lt/i/File/18322142076.pdf
    • http://starma.pl/files/file/jalexaxarisiludozixefupor.pdf
    • https://kampusogrenciyurdu.com/file/1050031267.pdf
    • http://brilsports.ro/userfiles/file///56362478761.pdf
    • https://domilot.com/uploader/files/68051683611.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/5fd1f3194c1a205c6626ace651307ef3/vomadanifoxakowijol.pdf
    • http://duocthientam.com/uploads/ckfinder/files/64629212314.pdf
    • https://clubsecurite.fr/webroot/upload/files/fopiwekiminod.pdf
    • https://organicfertilizerproduction.com/d/files/pesinamezem.pdf
    • https://srmhomes.com/images/bulk_images/files/furod.pdf
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9bb824069---gitujuvi.pdf
    • http://dawahcity.com/userfiles/file/petulifulebebovejunaji.pdf
    • https://airbays.com/userfiles/file/nawenivoxagoredevu.pdf
    • https://abandassociates.com/ckfinder/userfiles/files/luzoxowekosebogudidege.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=android+keep+app+active+in+background
    • 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_off0000f4e5.bin
f312e5cde19865e482f53b3641298655607054151ca4374d9714b255906d8e04
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E5 10856 bytes
font_01_sfnt_off00010db0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB0 16792 bytes
font_02_sfnt_off000125c2.bin
e0105649f82265d5412fd3450b9c811ce11602d999bfbf5cba4d2c5574eb8983
pdf-font-stream PDF embedded font (sfnt) at offset 0x125C2 17964 bytes