Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cbb17edd018fdff…

MALICIOUS

PDF

68.5 KB Created: 2021-05-18 18:06:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: a95f306179dc2ffb2803e2061e27cace SHA-1: 8a9a099c978fdd89e65c7e3846c2308b08606433 SHA-256: 8cbb17edd018fdffbb4be46ef75a90a6889b11e8b3aae8b284f1fc853d2b4603
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate that this PDF is designed to redirect users to potentially malicious content.

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://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/796b342bcbbbabb0524e080b9c03fbde/fosolesexuzijukepisul.pdf In PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/de9081054c77c5098c6738b0c1905f2d/69293048468.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cba24740e2---duvuxaminosorew.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/8ff4bd81629097de0a31bbfaee0be423/sujaduwujabizo.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608a866ce0018---84120683961.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609265113de16---82749027146.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607becb014493---31786437012.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607fee41c7d7d---85501741773.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/c263ba65f37e78e0d77799cb5d846142/18893880885.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160844d0ec7a82---48642007332.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c4d22697b---97511914958.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/6j7hu2q0ps0477jq3743s4t4pp/nawiroxikerovu.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/4863676d4f538e91cfa7fef6dd2460d5/18499931193.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c1475864504f48f11cd6303f2393f090/64956208017.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/3pqe19htgkfgv8ctqkck95gk0c/43118381673.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/e53117e514e9df647619392bc0dae243/3505401512.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/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=english+grammar+tense+bangla+pdfPDF 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_off0000cda2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA2 5552 bytes
SHA-256: a5fdd16e574d5b68739d97ab11532b0c70682670050dcceb5fdf6c488ff37c0c
font_01_sfnt_off0000e054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE054 10788 bytes
SHA-256: fee8743c9ec9b90084f99bbc8f0ad9074f24162d2b8b7bbe37ecb67ed56190b4