Malicious PDF — malware analysis report

Static analysis result for SHA-256 debf46a04f3a0d3b…

MALICIOUS

PDF

73.3 KB Created: 2021-03-04 22:43:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 3705149c63f8e1e71503a86612c8fcd1 SHA-1: 5b49df38bae7282f047696c49c7853b05e37ec6b SHA-256: debf46a04f3a0d3bd8cf0fe158a253e811a3d838ae57c0b81b2fd08bc7871639
126 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs suggests it is designed to redirect users to potentially harmful content or facilitate further exploitation. The document body is heavily obfuscated and unreadable, providing no direct clues about its specific intent beyond the link farm heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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://midufefew.ru/wix?keyword=learning+web+app+development+o%2527reilly+pdf PDF link annotation
    • http://odemebayisitrafik.com/what_services_does_primerica_offern5g8k.pdfIn PDF document text
    • https://zuvagojajom.weebly.com/uploads/1/3/5/3/135398962/361d30f2d6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393499/normal_6011f1424677d.pdfIn PDF document text
    • https://xiduzejeg.weebly.com/uploads/1/3/1/6/131606953/6521125.pdfIn PDF document text
    • http://itverys.space/tp-link_tl-wr841nd_als_access_point_einrichtenxzylz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426944/normal_6002f633973a5.pdfIn PDF document text
    • https://poginatiru.weebly.com/uploads/1/3/0/8/130874277/1554077.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473023/normal_6037f0df22c2c.pdfIn PDF document text
    • http://gratoramaa.space/android_studio_requirements_ubuntugf87x.pdfIn PDF document text
    • https://ruxapumuful.weebly.com/uploads/1/3/4/6/134682584/nejemonevuv.pdfIn PDF document text
    • http://glawerry.online/digital_photography_school_posing_guidee3gu4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500444/normal_60029773861f4.pdfIn PDF document text
    • http://xugerovogubex.22web.org/12311882288.pdfIn PDF document text
    • http://iceteas.space/puxuzimo7t4j1.pdfIn PDF document text
    • https://zugufavowi.weebly.com/uploads/1/3/0/8/130874222/594363c39070e3c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490263/normal_5fdfdfcc4319e.pdfIn PDF document text
    • http://istlan.space/attitude_status_marathi_dostipdouz.pdfIn PDF document text
    • http://baffer-shop.space/how_does_flash_chromatography_workh50ib.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9c43cb74-45e3-47de-9527-fda2e8336169.filesusr.com/ugd/af0aa9_a108f48f6d24486da4cf70c6f1aa7634.pdf?index=trueIn PDF document text
    • https://7ed754b6-a209-4558-9281-0032c7ee8ade.filesusr.com/ugd/4329d7_41eb8131df024bfe8517d6567b14490a.pdf?index=trueIn PDF document text
    • http://vovuvap.rf.gd/waposakubugerozopuwoga.pdfIn PDF document text
    • https://8137cd1e-393d-4948-8193-eca935452849.filesusr.com/ugd/756799_a1a8513b3cfa4689891618886a7084dd.pdf?index=trueIn PDF document text
    • https://6fd4412c-3e6e-4f21-a9af-8137ffc6c0d9.filesusr.com/ugd/03469c_0444b6e6e94547658d37336195cd5e6d.pdf?index=trueIn PDF document text
    • http://fejusudoboriduf.rf.gd/in_the_heart_of_the_sea_all_tom_holland_scenes.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_off0000e05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE05F 5552 bytes
SHA-256: 4bcfc4126efe856d13d9f0ff4abf0cc6ed9cabf9623450f79f7138cbf2147a72
font_01_sfnt_off0000f359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF359 10692 bytes
SHA-256: c74560b59adae52c8afe35a152571ec0f72f10c841d81ce6ae4df7994e39b782