Malicious PDF — malware analysis report

Static analysis result for SHA-256 db49494025dcb5ec…

MALICIOUS

PDF

81.4 KB Created: 2021-08-28 23:58:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a9579721a40f99d86dcfd8a22e1bfc3e SHA-1: e82c05be2328b5e95ebffe796857c053090b9eb0 SHA-256: db49494025dcb5ec1a47848e8d9219458f4434a2331e4d51a2bf95ec713feb64
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as a malicious PDF by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to various websites. Several of these URLs are hosted on compromised CMS uploads or disposable domains, indicating a potential phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is designed to leverage link farms for SEO manipulation or to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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 http://thuexedanang247.com/uploads/image/files/33175228774.pdf In PDF document text
    • https://swalaya.in/userfiles/file/tejubobew.pdfIn PDF document text
    • http://chinamakina.com/userfiles/file/39699276814.pdfIn PDF document text
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/92fdb68c12690154d905223c23452eb2/78118242035.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/c968e20e001b30740aa6bc85a3bc6cec/filizezu.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210509230835.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/nalamaxawivadobugiwixug.pdfIn PDF document text
    • https://demetraproject.eu/ckfinder/userfiles/files/tatudezavagerupawuzojo.pdfIn PDF document text
    • http://vo23.ru/upload/file/81823176748.pdfIn PDF document text
    • https://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/41ec8c7956354dd5febd131c09af2c68/dumalisororewujupu.pdfIn PDF document text
    • http://anhopphat.com/uploads/files/kosujugad.pdfIn PDF document text
    • http://chinasoftcore.com/userfiles/file///49157127574.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/5fd137e9eca9da53520dafd67bef309f/64849043918.pdfIn PDF document text
    • http://creativecoms.net/userfiles/file/tozefoxasiboxe.pdfIn PDF document text
    • http://liffeyartefacts.com/fckimagefile/file/texupawefax.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/ffd3b4a61bbe2c5bdac98a7054cc761c/77844579365.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088f95c7638d---tiviwinazidapetos.pdfIn PDF document text
    • https://dobski.pl/userfiles/file/xevupuxe.pdfIn PDF document text
    • http://186086.com/upload/files/kizojasedivizomararipu.pdfIn PDF document text
    • http://global-insurance-broker.de/downloads/5866635959.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/pinoxijuporurukujov.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606feed115955---99146517777.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/47299331876.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5017ae996---muzuxek.pdfIn PDF document text
    • http://herculesestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/muxegevokelujuvik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=critical+evaluation+of+research+article+examplePDF link annotation
    • 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_off0000da07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA07 11044 bytes
SHA-256: fffff3cfdfd3b45346aabfa3dde7f774f155543210fa5158db2f6d1c97fb1edc
font_01_sfnt_off0000f399.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF399 17200 bytes
SHA-256: 3af6b4f35b1e53dff697f5a18998e251e0e57812b00902ef95da95444d6c6f47
font_02_sfnt_off00011f32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1