Malicious PDF — malware analysis report

Static analysis result for SHA-256 31bfe578e7593a7b…

MALICIOUS

PDF

78.2 KB Created: 2021-03-28 17:56:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 9f66beb378c2b06d8f3a7ad7e834fd92 SHA-1: d6ac89f3856790b1df22773286aa7806fbb28442 SHA-256: 31bfe578e7593a7ba2db183e705e6e1c218a80f02ab87a28c32d6558e8144638
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, suggesting it's part of a link farm designed to manipulate search engine results or redirect users to potentially harmful sites. The presence of multiple external URIs and a link farm heuristic points towards an attempt to drive traffic to various domains, some of which are hosted on disposable infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jottigo.ru/award?keyword=gate+2020+syllabus+pdf+for+civil+engineering PDF link annotation
    • http://zebozewazogaso.scienceontheweb.net/ziguzetevurimuparuku.pdfIn PDF document text
    • http://gepexoliv.medianewsonline.com/science_and_sanity.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485012/normal_601251657443a.pdfIn PDF document text
    • http://suziterunedoloj.sportsontheweb.net/wiruletagezesamimofuw.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421061/normal_5fefbb3c128e3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420034/normal_602230baae7cb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/75f55092-bef7-4492-a1f9-7fc3bf097662/my_lasko_box_fan_stopped_working.pdfIn PDF document text
    • https://12dd324c-696b-4d67-8c19-991f3eacec2c.filesusr.com/ugd/eeb7bd_75ac390c05b342d78b1b6f145bb33e48.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/39822058-105c-4e1a-a222-a72dbc483cd9/tixufusoma.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a2e8a360-dfb8-4b89-9ccc-2424dbc56a9b/python_projects_free_download.pdfIn PDF document text
    • http://mijovutotukedes.onlinewebshop.net/54703750890.pdfIn PDF document text
    • http://mojenuj.atwebpages.com/anatomy_of_digestive_system.pdfIn PDF document text
    • http://pilejifizodan.onlinewebshop.net/twinkle_twinkle_little_star_violin_notes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/21557703-9843-43c6-a466-64ad0a828877/tizotu.pdfIn PDF document text
    • https://4dd4a32c-aced-41d2-87e6-7ff9ca8080d7.filesusr.com/ugd/6d6f33_0e7dc14b852a4ad593e901cb86d3eef2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/542a089b-b7bd-40e6-8836-03d9ef6889fb/powuzupow.pdfIn PDF document text
    • https://2e81f42f-67f9-46a9-89e2-a5f3ab3b03ee.filesusr.com/ugd/f138f5_a518751e94af48c3a281ab0021a1b5e3.pdf?index=trueIn PDF document text
    • https://7133fc40-0b9c-4701-b953-e7fafc934b44.filesusr.com/ugd/70a38d_565c85aba4d249f6b239458505adcbde.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8535e293-e3b0-4cf6-bf85-06b4220e78d5/37994157637.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/919eaba1-0df9-49a7-a793-624f826c7063/dikutetaboxejuzulojago.pdfIn PDF document text
    • http://sulenovigadi.myartsonline.com/91404812480.pdfIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF006 5932 bytes
SHA-256: 4c4b3e3215509744c8c64d268924181e925417971658c9d70fce2a59949b53c1
font_01_sfnt_off00010451.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10451 10972 bytes
SHA-256: 256bca4fd15c53e8b9a1aa61e08916995e8b27c7567d0a7ecf62af37abe78189