Malicious PDF — malware analysis report

Static analysis result for SHA-256 c88063df42f7e432…

MALICIOUS

PDF

84.4 KB Created: 2021-08-30 11:33:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7f760e2b32d7aadbcd91c422a2054a09 SHA-1: 1f14aeaf25321cbbe776bf6a78ce897e0a38193f SHA-256: c88063df42f7e432321883c18e67053bb557706206268db35aa65a9d0e589260
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable domains. These links are likely intended to lure users to malicious sites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://a-daily.jp/app/webroot/contents_img/files/57003400752.pdf In PDF document text
    • https://karinbentum.nl/uploads/file/79936264240.pdfIn PDF document text
    • http://industrialsupplies.pk/userfiles/files/sopiwexovaxeteratu.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c3cc36b09ca---zetufeku.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/0d26e085967eac2b7313868f6fd0083c/90072353876.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088683777ae2---52479415071.pdfIn PDF document text
    • http://www.chubsorn.com/file/files/12104885357.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/madaxesabisa.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c418afdc2e2---12173826941.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/megakavemuzisem.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608010f0c9822---6305178778.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/momap.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/13712219307.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607813fa74e25---31531315842.pdfIn PDF document text
    • http://taxplus.in/images/contentimages/files/jezefosobobukowaxoroxetav.pdfIn PDF document text
    • http://www.cpnatacao.pt/backoffice/ckfinder/userfiles/files/nudes.pdfIn PDF document text
    • http://csc-vietnam.vn/uploads/userfiles/file/13250563931.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/22632752040.pdfIn PDF document text
    • http://giga.sk/storage/file/misitipuwubaginubigo.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/7803662367.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160de5866f0d35---99852835722.pdfIn PDF document text
    • https://tekmaker.com/upload/files/davoda.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/5nptuc69vfs4cthiib0t777ee2/10367795129.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-6-25/20210625014614389320.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=flat+earth+round+earthPDF 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_off0000e46e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46E 18224 bytes
SHA-256: e22c81f0a8c402090b4b7d956587326d4d1224e8fd71659cf7cf842de15017ee
font_01_sfnt_off0001141b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1141B 10160 bytes
SHA-256: a5bf8377d7b36eff5011e57b843971da5c3d29c923d4e91e663b0c96727d0d4e
font_02_sfnt_off00012abc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1