Malicious PDF — malware analysis report

Static analysis result for SHA-256 caad6c83f569c164…

MALICIOUS

PDF

74.5 KB Created: 2021-06-09 11:34:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 1159809f40ba0c9d2dd5106e9b88f6cf SHA-1: 5b807189c46b65039550f165f9502792b8d01190 SHA-256: caad6c83f569c1647c639ca41d4f7d357721590508b7a7d1dbde748533b4f98f
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs pointing to various domains, many of which appear to be hosted on compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the sheer volume of suspicious URLs points to a malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • 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=watch+my+hero+academia+heroes+rising+eng+sub PDF link annotation
    • http://architettoseneca.com/userfiles/files/60559433610.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/5dcc7c78df6578644e1893d5a526a6ec/gutalawikovikipu.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cce3610d14---16517584319.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/fetadagekavowosop.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/45961489350.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/hvssijo54sk5726p3ueomd3iv1/wakubotozofi.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/1302fe564430a0ec36054790f8be036d/55667193811.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16094b51b43f6a---51064276127.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/2tsa8i0di92rv134u0dijp3kg7/40720704480.pdfIn PDF document text
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160906b97ed861---20955364623.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16099f94498a76---gewuripabajunuko.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4e6bb69fe---52813908408.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5279a8ebe2---wusufopesozatazolopifev.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/bs2jrsfpeng7gd7eut22ie6d80/28355528479.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a7d28dc5---45258271415.pdfIn PDF document text
    • https://bleikss.com/userfiles/file/tinedeloxexo.pdfIn PDF document text
    • https://thuaphatlaihanoi.net/uploads/files/tomogixigetosiwiruwawo.pdfIn PDF document text
    • http://ipublicity.cz/data/file/pepogudevotika.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_off0000e1ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1EF 5576 bytes
SHA-256: 8f0ae1a017e16a066d8730f8781c9c5cb6b64d784b9b93a6e8e4e091dc16b549
font_01_sfnt_off0000f4ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4CA 12344 bytes
SHA-256: d9034f58b610a153e28d3500b7821df171a2fe24f372e0d894d73281dfdac020