Malicious PDF — malware analysis report

Static analysis result for SHA-256 77490c4f787b3763…

MALICIOUS

PDF

81.5 KB Created: 2021-08-29 14:01:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fe0144c02109cccc42b48b1d030c01d7 SHA-1: d1da0a24672548feabf0ab0de156f1371388d250 SHA-256: 77490c4f787b376303952024496d19a15134a9d3e8547066aa6a00ad4c5713bc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. Heuristics indicate it functions as a link farm, with multiple URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to distribute malware or phish for information. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://sieuthivatlieuhoanthien.com/upload/files/gejurunimawonak.pdf
    • http://espacioschillout.es/images/admin/file/3228890586.pdf
    • http://zwickerfoto.hu/_user/file/zeniz.pdf
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/fa63fad92fbbf068ce06cde450dfc997/4679560960.pdf
    • http://nccutrackandfieldnation.com/clients/2/2c/2cea5a7e730406ee40dfbbde6098010c/File/wadajakomisup.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/09c248b5cfc03311acb821fb031414b9/jodor.pdf
    • http://panziofabian.hu/fck_kepek/11817126128.pdf
    • http://klpa.net/userData/board/file/tisumoparavujokono.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160df15fac86f5---gebimedudapalosogita.pdf
    • http://mispuntossaga.com/campannas/file/budezibe.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16126d61823797---jezakef.pdf
    • http://robalton.es/Albums/images/file///dufamomavegenepodo.pdf
    • http://naosgym.com/userfiles/files/35929075597.pdf
    • https://contabil-fiscal.ro/mm/file/65178485387.pdf
    • http://aven.su/userfiles/file/62928078560.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/58198cc0e7918d5362e32b92edb0d79e/kevojuluwununaxurezaso.pdf
    • http://droprint.my/home/ququ4923/public_html/userfiles/file/56361542164.pdf
    • https://bwawarszawa.pl/upload/file/pidederineruviluxelad.pdf
    • http://ehomeforeclosure.org/images/file/xifotidepexabi.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b6f08b14a1f---dulafobekixawizabib.pdf
    • http://pogotowienaukowe.com/Upload/file/67076124132.pdf
    • https://widerbet.pl/userfiles/file/40779239910.pdf
    • http://gaishachuukobuhin.com/js/upload/files/bubaxilugetun.pdf
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1950764996---17829007348.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+manually+measure+heart+rate
    • 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_off0000d9cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CF 16792 bytes
font_01_sfnt_off0000f1e1.bin
978efa36c1147d72949e7d31a8f423737d2fe510e93caf3008403ec2dedca9b0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E1 17532 bytes
font_02_sfnt_off00011f77.bin
cc518f43f47c8016501f5b2bf832f75f911a7675de111b4410739fe417feb587
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F77 10572 bytes