Malicious PDF — malware analysis report

Static analysis result for SHA-256 f057082313d7909d…

MALICIOUS

PDF

71.8 KB Created: 2021-09-30 19:00:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9bc1cc427136aaa43492d44bb56a6620 SHA-1: 1f32863eec02bf2f9f7e3cc60cb37643cc0a72be SHA-256: f057082313d7909d01ad3d533135c750ef807bfd32e7b8ef14cb0ebdeb5036cf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a link farm pointing to multiple disposable hosting domains, some of which are compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

Heuristics 7

  • 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.
  • 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 https://medvor.ru/uplcv?utm_term=perloff+microeconomics+solutions+pdf
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/fijivipusep.pdf
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/55t4v9ejcraavuiljfluj7905s/36864823683.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613707d5d6d31---banibirirurek.pdf
    • https://roxracing.eu/userfiles/file/47106942199.pdf
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c340e0a3cd---13379455401.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/64062ecad7b19aca043bbdbc5d893733/3910404740.pdf
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c0071019c---manuzuvitajojolojiba.pdf
    • http://radyoislam.com/resimler/files/rusijenapi.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16149f9b7498f0---supanewekulugokote.pdf
    • http://lamekatus.ee/uploads/ckeditor/files/kexufi.pdf
    • http://sozopolihills.com/userfiles/file/45952059699.pdf
    • https://rezilta.com/psum/admin/userfiles/file/7839003570.pdf
    • http://www.portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/51710408426.pdf
    • http://derp74.fooden.com/UserFiles/files/59923942776.pdf
    • https://kotata-zlin.cz/obr/clanky/file/gadusanenumegi.pdf
    • http://orchid-daikanyama.com/userfiles/file/42781938008.pdf
    • http://namlinhchivietnam.net/userfiles/image/file/5741698030.pdf
    • http://www.darvidproperty.com/news/file/jesugogipetib.pdf
    • https://bawwabatrizq.com/userfiles/file/99455516204.pdf
    • http://eluvial.com/sites/all/sites/eluvial.com/files/89416645879.pdf
    • http://autodilykanka.cz/cmsimple/images/file/49347642472.pdf
    • https://ecpa.fr/uploaded/file/73305559894.pdf
    • http://keemunblacktea.cn/uploads/file/200040443002.pdf
    • https://store-connector.com/_upload_bilder/_filemanager/file/kidolepaj.pdf
    • http://air-ned.com/uploads/files/rewamasivibabilo.pdf
    • http://4seasonstours.in/userfiles/file/bajomogasajaxajalimud.pdf
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347d1e4ed11---25436347945.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_off0000b7c8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB7C8 16792 bytes
font_01_sfnt_off0000cfdf.bin
31687138c245c87aaeaf73396a192af79eeb17cfcf70dde4ea85d5e366bb6e77
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFDF 10720 bytes
font_02_sfnt_off0000e874.bin
fd5a8b52f4a333afe49e7d576f2bb278c48f15a560af0e27bfbbc0cc3ddd9f83
pdf-font-stream PDF embedded font (sfnt) at offset 0xE874 15996 bytes