Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bcc3e4728e08795…

MALICIOUS

PDF

74.4 KB Created: 2021-06-09 14:22:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: f572143f183b43413734618292819e85 SHA-1: fe3db1f9b114e1a4fe17c08fa3ee37e37bd3013d SHA-256: 4bcc3e4728e0879585919d55b5a636c7949417809e8cf110fb33e2548adc6054
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as Pdf.Phishing.Trojan. The file contains a link farm pointing to numerous compromised WordPress sites and disposable hosting domains, suggesting an attempt to redirect users to malicious content. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics indicate a phishing or malware distribution vector, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://archism.ru/uplcv?utm_term=standchen+serenade+schubert+pdf PDF link annotation
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/21ab1d223a11cad98d89d1321b93e5fb/52520531521.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/6ughjgq0vtsuufepqa91g9cos6/8275131544.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608caf2067212---7518952559.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/ae11f01f20ddbef5d2f883831dc35f7d/62569662860.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee3b67746c---kumanarute.pdfIn PDF document text
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/7953078052.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608077d8338e8---31443387752.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16095ff59498bd---vubulepawemaduzew.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/dd5oalsehf17adpim7qil15pbb/24003563411.pdfIn PDF document text
    • http://apsons.eu/files/file/garigugosuvokisuneb.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/52bb0fc5915ef70b3654f79f0a877ab4/55842550726.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b0946a00ec5---86869342168.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098989ea4005---nutifopevafukidiwivuxux.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/cfe807a5dd5c045a7f01f80734dcdd3c/pamokezikusex.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_off0000e38e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38E 5452 bytes
SHA-256: 8c1303016adb8969a1e67166fa5a51f0a100aa12d23d3762d2b9ca39fcba5f0d
font_01_sfnt_off0000f60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60B 11284 bytes
SHA-256: 86a7b75cab5748aaff4712ad2610e368d089f13f10a8c801dc65e20b5529f6e7