Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ff9f3f9221b3f1e…

MALICIOUS

PDF

78.2 KB Created: 2021-06-12 21:33:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 39490e26c1fcafcb087f317de276a907 SHA-1: a1bf49723ec3c584099c5127dacf76625a44097a SHA-256: 4ff9f3f9221b3f1ece8a9ab2c3218abb5aecb1bb963dbb66d77b313ca7968a8f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that form a link farm, directing users to compromised WordPress sites and other domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. The presence of multiple compromised CMS upload links suggests a pattern of leveraging vulnerable web infrastructure.

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://crysiq.ru/uplcv?utm_term=stand+by+me+piano+sheet+pdf PDF link annotation
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1608537170854c---22649411623.pdfIn PDF document text
    • http://kythuatviet.vn/uploads/userfiles/file/89066282945.pdfIn PDF document text
    • http://candientushinko.com/images/file/68086459689.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16093df0600d61---17542569564.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/06d468ad824f986ab125d05846079d9f/galamutode.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/d7aa1e4c07dcb3642eab2635f1b97931/kewevuzeturimomiza.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160836163d64f7---11378283073.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ddmh72ifsrscq5liq72vs1f7vc/26818449229.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a278fd9b870---17925549542.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/apnl16oqs5f7926kpgoluh7da7/futular.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c9f1ab8ba---1837287396.pdfIn PDF document text
    • http://run2endalz.org/clients/2/2b/2b4973775a35d8819257a28a16fdea67/File/17591397760.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/41crpgdbh15n3in4dag9h1pll2/miwuxefebiva.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/55834222498.pdfIn PDF document text
    • https://vestol.bg/files/file/84695544780.pdfIn PDF document text
    • http://cezanart.com/userfiles/file/79594065422.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/a5bfc366de8a8dd829fb7ed278d5b993/fujopitagugimemimofonan.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c3dd5f96223---43129786146.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E1 5284 bytes
SHA-256: 36100bf43a1a9ece06c20f3f5c26919355e8a1ac9098087d88e6935ece5129b7
font_01_sfnt_off0000f8ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8AB 10824 bytes
SHA-256: 6bde978b5ae60ea1546a603eb7a8acac934270681c960c39f3d8ae2e0f777bac
font_02_sfnt_off00011d9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D9A 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e