Malicious PDF — malware analysis report

Static analysis result for SHA-256 4978a33aadb46301…

MALICIOUS

PDF

74.6 KB Created: 2021-06-20 19:58:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 4eca8a9c55603791b4c6ef8b89c51241 SHA-1: 201a0b27964b320a568527c83a81c7146ff8cbd0 SHA-256: 4978a33aadb46301cf2e742f4422d5bcefc4fcbe5ac37672158926231437b747
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains multiple embedded URLs, many of which point to compromised CMS upload storage or are structured as link farms on disposable hosting, indicating a phishing or malware distribution attempt. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristics strongly suggest a malicious intent to redirect users to external sites.

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://a2designbg.com/userfiles/file/kibivumilafokubajatel.pdf In PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/41a43e7c2bc57c76056a427741931491/vinumizofibison.pdfIn PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/8da28d7cca50994ba713ef6cfc833680/kedukutelegogeg.pdfIn PDF document text
    • http://bosch-service-center.ru/uploads/files/nokuxazaseti.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a8f9eb0ddd3---51103371063.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/f7d699e62385b97ac5994c98b7d41083/gowiguwimefonezelora.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/74c7ede997a6d83ebffc5f584fc1afd0/nexogobakazabi.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/4122458a7dd280c8d3dd3884bc26c059/81524506232.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/39r9pccuaq60susr67v2ddavus/nojemitozidudugiw.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/kiamuulqt1c2kna7olg08fe0q0/5961676210.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b25600a4ec---53449494228.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160aab9fb89cc8---7530240573.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607912ab1be31---60366585079.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16098807851711---99553361401.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
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=article+writing+class+9+formatPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FE 5228 bytes
SHA-256: afbcb6b2a81466324d412c2a63c4dfe5cd7d09e710c2fbf50698c8c942faa7bb
font_01_sfnt_off0000ebb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB6 10564 bytes
SHA-256: c1b4979944343a23cc5329c8d9e8260cd153828fe5a4a67024ca2d437c4e7679
font_02_sfnt_off00010f8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F8F 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2