Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a86d50d1956273…

MALICIOUS

PDF

80.9 KB Created: 2021-09-01 23:51:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d9817eb778cd8b9611468e816c67419e SHA-1: 373f520f3f82ecd10217deab3f27685c4180d56d SHA-256: b3a86d50d195627394137690b44cdcb58899fb3031ebe90da6277a228a2d5988
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by multiple heuristics and a machine learning classifier. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection further confirms its malicious nature, likely as a phishing or malware distribution vector.

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://schokobrunnen.com/idata/sodugirotisazerexidorireb.pdf In PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/33d7b70f3b7ce3f2789cfb371e435de3/sagakilekokejokepiku.pdfIn PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/2c482c2b342c4710936802f891a30a42/soxavoniwon.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/78875650251.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/3832f40e5445c036c3fd1c0b6085d45e/29936453775.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/9of6rc6k80dmmrr5211v2t9pd0/ropirumegematinerujaxad.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/lorepid.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/b3c7c731a9120c59b50bda691de2dcca/babubinatuxamukebamag.pdfIn PDF document text
    • http://hibertek.com/image/files/20210722_124900.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/7306b2e08e962ca7b51576036fd0b84e/vipejakarizagabusifabiwab.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/25712147238.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/womokabunuko.pdfIn PDF document text
    • http://mesahighclassof63.com/clients/79820/File/munuxexuwefavewiw.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160896ba891401---jukaronakurufenojufe.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8528bcfcbf---57093344387.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210428113849146.pdfIn PDF document text
    • http://jx4d.com/userfiles/file/kunabaforimejijera.pdfIn PDF document text
    • https://www.myosiaffiliate.com/199trust/img/file/74189989178.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/4ae66829e96c6b0aaa5d64025650badc/93637822132.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bcbb9d0c3bb---busanalowebowodegotu.pdfIn PDF document text
    • http://chinajnbt.com/images/upload/File/kulix.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/ae77b21d1a210e576ab32be3ef7df2de/jutekibagetapoxowadedu.pdfIn PDF document text
    • https://soechi.net/userfiles/file/kesuvewowokebapojexo.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/gonikipopumiluz.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160d234c1e526d---tununaseben.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=terminating+a+subcontractor+agreementPDF 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_off0000d89a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD89A 10732 bytes
SHA-256: 3642aeef193bfca34a46b98431b62648fe4677678a0b0edbcbdb318d2adcc6b4
font_01_sfnt_off0000f145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF145 17100 bytes
SHA-256: 630aa1bfb107990c37a03259a5b1658c661894e2279a8705864bf9ddcaf44829
font_02_sfnt_off00011cb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1