Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c838820bda7a35…

MALICIOUS

PDF

93.7 KB Created: 2021-08-08 14:14:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 52981c7b82902f3303f63c0fb666f96c SHA-1: b2bd58caea75d61216a0c64ae20abe5a106d4d13 SHA-256: a5c838820bda7a356e6c74915c177c62489edbf2bf08a225c9457c69cf46a714
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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.
  • 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=how+to+make+animation+in+pivot+animator PDF link annotation
    • https://birsamundapark.in/userfiles/files/24769384733.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1831858640---pexow.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/lgb1kagg7pb3iut100q7qp5ogq/saxob.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/46e50118d4aff737f8ebad6a7c3d0590/vowupudowisex.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/6965224000.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/91510037039.pdfIn PDF document text
    • https://bharatbiodiesel.com/userfiles/file/jexorapegananetida.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607b50b676ec2---43007448449.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b70c84d5f---91619296132.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160d9398604998---wujuwusov.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c66ab8f3b---rejom.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ln01f3g9s6pv4gamu9t7oae180/fibarurulibib.pdfIn PDF document text
    • http://bakoca.hu/files/file/50140892887.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/zaxurifubazowebusej.pdfIn PDF document text
    • http://www.alquilerbares.com.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1607260e906b46---jipuvexafiguvigunuvivena.pdfIn PDF document text
    • http://shiokuda1.com/contents//files/sepifuteboromuvepiweditig.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160fcdf8f76c7a---10465420305.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/37c2d66b15789b06bef76a47be1c22bd/refokemixikan.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075f6db70553---dipemowarureri.pdfIn PDF document text
    • https://interior-mark.com/ckfinder/userfiles/files/78308239179.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/8o3i2c820ghskjt3fns2gd6at5/66564401015.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16073649190c07---28748477011.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/17915680134.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/40e560c511238efb762cad4a3dd0002c/tuxokijijekizokumibava.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae01911b55---29828675356.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_off00010dc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC9 16704 bytes
SHA-256: 8b31f44dd063271a4bf1849f2a1ed1b6c22137c45b667532be93640b1ca919a0
font_01_sfnt_off00013912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13912 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015129.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15129 10432 bytes
SHA-256: 2188e668b910d967af211f4d78996561500ad82f17b53f75ac0c1e5d5ec03c7b