Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff67cd5b9476169a…

MALICIOUS

PDF

72.5 KB Created: 2021-06-22 12:00:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: f74d7c47ac444ec1ca3355ac89229988 SHA-1: 18c5e13a6eef67ea9cf34fa09d7173a308e51cda SHA-256: ff67cd5b9476169a06a1f28efdc1c50a28f582172ec707d4b0c1630933d8782c
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded links, many of which point to potentially compromised CMS upload directories or disposable hosting services, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious content or phishing pages. No scripts were extracted, but the heuristic firings and URL analysis are sufficient to assess the attack pattern.

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://seripin.com/calisma2/files/uploads/92870647103.pdf In PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/8d0c7531165008beee6692f32a98b449/lisiranipazirumovofowifon.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/fedbg8hrqtcg1s3fdaig93clu4/34863246745.pdfIn PDF document text
    • http://www.asslar.de/downloads/dakapeso.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/a287973d3941041f916d49a2749155ff/27185904326.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160828f971fe3b---rutizoxom.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/8e18b8750a74f7f4b80ed99816ddfee7/bagaj.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079f899cab93---55809358378.pdfIn PDF document text
    • http://artin-intranet.com/ckupload/files/59451913850.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607460dc9fdf0---wojuwebar.pdfIn PDF document text
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/130829771cc01267e99784e2fb007fd4/sefefavozusukopoxamov.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7f9e21c59---23583045769.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/20216221622328605.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/gideruvibaluniraduf.pdfIn PDF document text
    • http://hydrem.ru/images/file/81835237579.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/m2caqcosdrqfem886qb8v6p514/jobopobedebowebezaxovug.pdfIn PDF document text
    • http://www.celso.org/download/46062841074.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=low+level+format+tool+serialPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e061.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE061 5008 bytes
SHA-256: 328e548b5a5c1626dc7220a08e28b38fcbc291aa48634220b92ff7e5ce5d65ca
font_01_sfnt_off0000f168.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF168 10584 bytes
SHA-256: 9726c12d1c2f86fc8c122ca89455bd5ad95ab6b41e3d7b8e7d5776a71fa8a9ee