Malicious PDF — malware analysis report

Static analysis result for SHA-256 486a596bc2a8d63c…

MALICIOUS

PDF

74.3 KB Created: 2021-06-12 23:24:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: a5ef8a8f608dc9a265c23b08c871b80d SHA-1: 287f0a6ae8aeca6d0dae8c759c9ebf31f4504c39 SHA-256: 486a596bc2a8d63c5af81ef63286e272a646b6b2960df1c48aec95c7e83c43c0
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs pointing to compromised WordPress uploads and disposable domains, suggesting an attempt to manipulate search engine rankings or redirect users to malicious content. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=the+various+forms+of+energy+worksheet+answer+key PDF link annotation
    • http://18554080.com/userfiles/file/36064482947.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/81269806422.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/49246033084.pdfIn PDF document text
    • https://bataretak.com/img/files/file/gezutagufetex.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/9cekfj6et4dd0qq9g6tvrg83gg/xufabuxiv.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/61253628608.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd8d85b6a7---zewenemozevoterugenu.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb41e171f3---tudubika.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a12c2d03908---joragux.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/528fae0fe3ed6e2545c7e4f177f1fc87/70572262781.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/buvusipizosa.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/2egne3pb7i73sobgjdl75tavbh/tapinabositixukezununor.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/17753700913.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0f978800d---25615059491.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084eda8ef510---84801771805.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/858d546046b20fd1c600b147135d9cb6/rezovozizidafobajimo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE466 5416 bytes
SHA-256: 7bad85b6707c6b0c7c8ce99fdac183915a52c765b15c60faf2044f9249f7b5db
font_01_sfnt_off0000f6c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C6 10656 bytes
SHA-256: 1497cfe075e965492069b6d3653479709d607f76a7687f37b68e37af17eefa2c