Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef539c10ccfe9116…

MALICIOUS

PDF

71.2 KB Created: 2021-09-26 01:34:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 28419fed30be7b223d20443a7c20f5f7 SHA-1: 12a399ab05416741ac41f4c4b77cc67ea4ca1e35 SHA-256: ef539c10ccfe91164b8a18fa0281e71bd0722c3c478347eb959fa6f70d04ee68
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://oniceh.ru/uplcv?utm_term=boxing+helena+full+movie+123movies PDF link annotation
    • https://medarbindia.org/ckfinder/userfiles/files/zegijaniderolezumiki.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/zisorexusuxidefawilodakuv.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210909_DF41A0A1A0E51909.pdfIn PDF document text
    • http://knipia.com/userfiles/file/54803985343.pdfIn PDF document text
    • https://tckontrola.hr/files/pomijifora.pdfIn PDF document text
    • https://bitree.com/ckfinder/userfiles/files/jomokij.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614cd7c2225c2---22043097057.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/tarebeputesudezezatoxof.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16139f87f239b6---lukokatetubaronakir.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/rruffahscru03ptob6kdfubn4v/miremeg.pdfIn PDF document text
    • http://airmon.hu/images/files/65430737861.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/zunumazeduvax.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/12915743688.pdfIn PDF document text
    • https://rosettes.it/userfiles/file/kewaxug.pdfIn PDF document text
    • https://norservis.com/files/files/gofexosazifatunidib.pdfIn PDF document text
    • http://ckud.handysociality.com/upload/files/60048507121.pdfIn PDF document text
    • http://mail-ex.net/userfiles/file/89428327578.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/91816171054.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/50257258700.pdfIn PDF document text
    • http://nhatrangpalacehotel.com/app/webroot/upload/files/wavimujevarurowetinezafo.pdfIn PDF document text
    • https://vietucmould.com/img-vietuc/files/11308342541.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_off0000ae04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC616 17592 bytes
SHA-256: 3c20a942d25495d873c8fcca891b1a069701177a6c97c08b8f99d7d996416ba5
font_02_sfnt_off0000f3cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CD 11128 bytes
SHA-256: a6ffa286d728beee7045abdf248a1baf3f17571c483d845f7e277d8ef560c155