Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31a1070c6d7d997…

MALICIOUS

PDF

95.5 KB Created: 2021-07-26 03:48:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff2adbe4856fd6d8770e2bf11b6c1d3f SHA-1: f6455715ebf7b64f42c115be8583940023b387d8 SHA-256: f31a1070c6d7d9979f238c5e446adce450ee8ccb09b2475fbf49e7471facb483
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution by redirecting users through these compromised sites. The presence of embedded JavaScript suggests it is used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093eae064db8---43906737924.pdf
    • http://akinmedikal.com/uploads/file/ramogiraje.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aa331c9da43---gepixo.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/folibaru.pdf
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/8cf3b4da334859bb40981f1ea14f68a3/tosezopurazukadasu.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/kq5sq85q7lgv4kt1mbak38rfue/41444881813.pdf
    • http://fructusartis.com/i/File/piwisunumekevuxejevozon.pdf
    • http://www.msjcongregation.org/www/js/ckfinder/userfiles/files/wobipidid.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ib36bkoc3fktb14tj0prtc7as0/rotowowomijo.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608130068fde0---93862536050.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/239e77d67cac0cb37b30a1fc718808ac/zipepawelenopobiluto.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/17254171524.pdf
    • http://jaika.in/images/documents/files/tixutub.pdf
    • https://secolink.sk/userfiles/file/senaluno.pdf
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160795948d65cf---rimojorefepa.pdf
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/kolarapisolakapamariv.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc5fc1c85d---waxelokali.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/285c581bfee90ab50552ca11e00d067f/duwufuburazafojofigabap.pdf
    • http://northphoenixmustangs66.com/clients/4/4b/4b49b54eec06ebba3741256e9f3e6f2b/File/54925217553.pdf
    • https://hmanagement.net/userfiles/file/3742404281.pdf
    • http://mikailang.net/userfiles/file/20210502131424_950264635.pdf
    • https://ultralloy.net/upload/files/36741560498.pdf
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/7839b37acc3d24a65faefe8f985b4f6a/86132557080.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16098f7fa2d9e0---dusifovuvajodarukakobutam.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=are+quarter+pusher+machines+legal+in+florida
    • 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_off00011057.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11057 16792 bytes
font_01_sfnt_off0001286e.bin
a7a81eb1d4c5ba2a12631790da6f0227ea227c4053c668388711e00213248291
pdf-font-stream PDF embedded font (sfnt) at offset 0x1286E 11292 bytes
font_02_sfnt_off00014244.bin
00e22cdb4f8095bdecdbb13278df3edee87537d46517ecfa94b230eec2cac490
pdf-font-stream PDF embedded font (sfnt) at offset 0x14244 17080 bytes