Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a6198723fb0d729…

MALICIOUS

PDF

84.1 KB Created: 2021-09-01 16:51:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9405b79f44adf0c4b3c4a0a49ca7d000 SHA-1: 36f25bc419a5bba96fb1d991cd1f0974d9be3a18 SHA-256: 3a6198723fb0d729038332af1409f0b1443633fb3c6c5c9b75a07a37936d5c10
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features numerous links to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving exploitation of PDF vulnerabilities to deliver a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=how+many+weeks+is+it+in+a+year PDF link annotation
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/101634aad9247fa97f3df56eb0530e8d/24621392116.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/73692c879ffb4f914f4316d2fe1747d4/6423910870.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/zavoveteb.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/2d2254d693c2ea72532293d69b6f8af3/80269464343.pdfIn PDF document text
    • http://plantessentialoil.com/upload/files/vojunepopivekodon.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/gutazoxomebemebixebu.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/8jlrt5lntoup3n77193qva2de5/49374000992.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/toranojisigafidanogobola.pdfIn PDF document text
    • https://guenangequitation.fr/www/site/js/ckfinder/userfiles/files/bebijubexosefonowexetorav.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160755685cea7c---73918172546.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/6c6l10t1lci8ut3cebdhdg5iq3/polinuxiguwo.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/keluzoxitekem.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/9f5f9438277374bc72d67255dcffaddd/lufanutapunuketiw.pdfIn PDF document text
    • http://www.espace-hotelier.com/ckfinder/userfiles/files/13447215092.pdfIn PDF document text
    • https://berbagiangka.com/contents/files/muguzipezarow.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/13329713203.pdfIn PDF document text
    • http://salon-urody-bellis.pl/images/file/93374679581.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a227da2e6e8---xapofizolidijoromuwodige.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/wifovudujas.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160905b355dfac---11401110353.pdfIn PDF document text
    • http://neodermclinic.com/file_media/file_image/file/zugeditewigudadug.pdfIn PDF document text
    • https://swiz.eu/files/editor/ledaguvimasitefelebuzuz.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/86466081777.pdfIn PDF document text
    • https://ever-progress.com/upload/files/wafazowuwaseviwokiboli.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/94597086090.pdfIn PDF document text
    • https://eitmedu.in/ckfinder/userfiles/files/24888096775.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160c3cdc4ce619---xularubisavaku.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cadce97ada---99189242616.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB5 19256 bytes
SHA-256: c6260b84c2a3e47ab7ca1adc62728d874847a9d8024c7193e6efede107121e48
font_01_sfnt_off0001121b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1121B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012a32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A32 10504 bytes
SHA-256: ebd3128f13a049e1422008f0a38577bd9313053a4ed47550ab8f4a25b6cd0032