Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3417484af3e06a1…

MALICIOUS

PDF

80.6 KB Created: 2021-09-02 02:00:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a2c8b9b6a604ec751669aa2a339f4a12 SHA-1: 9f29f00c75f7c9983d25d8d60a3eed2cb44b9cfe SHA-256: b3417484af3e06a1057cba78ff34fecf18c29500aee5171b0e1ac533f4810835
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing an embedded JavaScript stream and a large number of external URIs. The heuristics indicate that many of these URIs point to compromised CMS uploads and disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://nomylo.ru/uplcv?utm_term=thank+you+for+your+collaboration
    • https://fizjolech.pl/userfiles/file/37360955109.pdf
    • http://medicaldistri.com/ckfinder_files/files/77809892210.pdf
    • http://aceonlinementors.com/userfiles/file/93354998614.pdf
    • https://sasalidayanisma.org/uploads/file/42416275646.pdf
    • http://sobinco.cz/ckfinder/userfiles/files/tevevizu.pdf
    • http://lifemartrealestateconnect.com/wp-content/plugins/super-forms/uploads/php/files/mkri31fme363h96aq932c2d0j7/86784831183.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/g8mfauel2s7aifrvsedaeuh725/16892370770.pdf
    • http://thucphamchucnangmy.vn/uploads/files/xowujatuva.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/6cn0l6r0vmsrs28kb7uhqafbj1/puxemobi.pdf
    • https://kisikana.hr/userfiles/file/suwexeruvipawopifasifi.pdf
    • https://codecs.ro/images/file/86112292175.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/fj1vj34eq7329tmh1km7nau2ph/52974261025.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/d11711023f2d59bbf025b3301bd776d5/85652873015.pdf
    • http://nguyenquangcomputer.com/upload/ck/files/44648837625.pdf
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16105c2835a43f---kugawetojosoxepubodonat.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/kfj6bcvj6a2u1o3m97qambios8/97646705688.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f1d4ed81d---bekuz.pdf
    • http://kartywspomnien.pl/uploads/assets/file/guletika.pdf
    • http://rc-modeller.se/images/file///6613218136.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/428820cd32d12f24399a745c6b0e3a62/50140962538.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/87951811701.pdf
    • http://holzbau-napetschnig.at/wunuwikodusu.pdf
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/9d740a3c46a959873a9399d4776b86cc/fogujobur.pdf
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/58408923590.pdf
    • http://4grd.com/cmsimages/file/dapukurodatopaw.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c34dbace963---binonopudepubep.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_off0000d822.bin
ff0ecef08fc15fe18c10b2ab041136de8da5e43138a91743083ddd9e6e078781
pdf-font-stream PDF embedded font (sfnt) at offset 0xD822 17452 bytes
font_01_sfnt_off00010489.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10489 16792 bytes
font_02_sfnt_off00011ca0.bin
3eeb3b2bdcf89ff0c2a58a2eb14685345ca629d97b6c252acfb57197bc907c64
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA0 10540 bytes