Malicious PDF — malware analysis report

Static analysis result for SHA-256 525f25b243234e04…

MALICIOUS

PDF

75.1 KB Created: 2021-06-27 08:27:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: c1de000f14450615ade40784002c6df6 SHA-1: e86adb167c956fb14892d4e67af5aadcc408d6dd SHA-256: 525f25b243234e04ffc400049f7736d6d551d173f4550cd1082808ba39a7028d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm, likely to improve search engine rankings for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The presence of external URIs and link farms suggests the document's primary purpose is to redirect users to malicious content, potentially for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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=human+and+social+biology+cxc+past+papers+pdf PDF link annotation
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/h98lcqhbetcer3k7628od94or2/mojabapelamusitenove.pdfIn PDF document text
    • http://al-farh-iq.com/upload/userfiles/file/vamozariwivanonozatovis.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/22574796740.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1b8266f89---951805905.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160783579c5eed---puwimubopadup.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6cf3d11bf7---mimixanepalorozojuxi.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c84f2200261---77839798063.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a37b1b258e2---11295308161.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b523a641727---jidepego.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/bakidamemagamifinuram.pdfIn PDF document text
    • http://bydnjl.com/userfiles/files/1882692742.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/030116459597.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091f2a2dffa0---58786894891.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/hsam14loskth7uqa2jgmoq8dat/74769303805.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/ua7e7car2h5u5djteop9hjml36/bapolomugizarudutes.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4ef262673---71957039799.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/lotabufilipuwupisik.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/wagezubevafukef.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16079dccbeb14b---8217442641.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/85039757887.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16072e4177b20f---90767184815.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9ca231216---jixuwewe.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/5bdb1841c72a17772cc18cd8b55478cf/80489767371.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/70637967480.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_off0000bfa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFA9 16596 bytes
SHA-256: aceba8323f94bef61e73cd5caf78d366981c18cc8200efeceee014bb40c67fbc
font_01_sfnt_off0000ea79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA79 11412 bytes
SHA-256: 1f18c6bf41ba492b7a66d7c995941ef2bff86fde90e7e8e0cd129e7f46ac824e
font_02_sfnt_off000104f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1