Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1f86aaa04bfb2d…

MALICIOUS

PDF

93.5 KB Created: 2021-06-29 02:12:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1acf7719e98647b521cc3f7997b7b8a6 SHA-1: b8a476b438117b53621ead5e7544135be3aa578a SHA-256: 4b1f86aaa04bfb2d6f2001547d2401efdb8bd6d55584aec0693841e242e1b52e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. No scripts were extracted, but the presence of external links and the nature of the heuristics point towards a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://catamma.ru/uplcv?utm_term=synonyms+and+acronyms
    • http://guides2alpes.fr/uploads/file/vuzenaxomiradofapek.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160d9e9d29e4fc---pexagaxebafe.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d87b888bd1d---91496087822.pdf
    • http://ondrejkocar.cz/img/file/76317691576.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec3f35de46---lakovukok.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ged85i33771rel2147t8ca0qn4/xumegijevipid.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ecac3d625---39600915198.pdf
    • http://cesurmakina.com/userfiles/file/giwanajazopojefolivov.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079540198dc3---44155631377.pdf
    • https://coolingrealestate.com/your-home-cleaner/FCKuploads/file/xoleduvoma.pdf
    • http://bahtiyardishekimi.com/fckfiles/file/nawapenofeb.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160872a4c2c2cc---11874396615.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b0a519cbbb0---duzub.pdf
    • http://www.kickcommerce.com/userfiles/file/50076774178.pdf
    • http://smflow.in/admin/uploads/file/kififavegegone.pdf
    • http://myjobcareer.net/userfiles/file/2021052200452973499.pdf
    • http://drjoecarver.com/clients/49355/File/13159178255.pdf
    • http://usa-ex.com/14810967140.pdf
    • http://microcement.ua/userfiles/file/10257070419.pdf
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/p21tbqul1rgqji3iggk2l1bjs0/gokit.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/f7d8bd721f434d1764d967e06ab49874/1802940532.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/4m08t8cs2rfmsdg0qa1v8r4ncp/liwaliro.pdf
    • http://4grd.com/cmsimages/file/67062987666.pdf
    • 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_off00010b03.bin
0b916dc41df8e6d94c49a3a89a80f2814d9edc6eeffa35da4e75c4b9c84a48c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B03 10352 bytes
font_01_sfnt_off00012256.bin
c244b3c9286810d4f456d277cb56c3e85c0a17012f802105b47f15610e991cf0
pdf-font-stream PDF embedded font (sfnt) at offset 0x12256 18036 bytes
font_02_sfnt_off00015100.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15100 16792 bytes