Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b1aafb2826077e…

MALICIOUS

PDF

117.9 KB Created: 2021-05-11 20:44:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 8e8f0501660b637f436ce62439120d92 SHA-1: edb8216b516f993fe3e8b7333162ec86b829ea26 SHA-256: c5b1aafb2826077e691b8b195c9c27d770558caa13bdd1b21f19c5fecdf1d6c5
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious. It contains numerous embedded URLs, with at least one identified as a known malicious redirector. The document body is heavily obfuscated and appears to be junk data, suggesting the primary purpose is to host malicious links rather than convey information. The presence of these links strongly indicates an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/strik?utm_term=forgotten+realms+map+5e In PDF document text
    • https://cdn.sqhk.co/tusadopovet/jhaYrWE/fashion_all_star_jersey.pdfIn PDF document text
    • http://jijimaxugixu.22web.org/34350355348.pdfIn PDF document text
    • https://cdn.sqhk.co/wixefawoz/egfjghU/othello_school_district_calendar.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454813/normal_605848f538ba5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4386335/normal_5fe40a2010fb5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491175/normal_603089a08370a.pdfIn PDF document text
    • https://cdn.sqhk.co/kotolodegag/aidieif/xulosaxigipedarewume.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369788/normal_600ee51909998.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4493579/normal_6003cdca53682.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://uploads.strikinglycdn.com/files/ddd29685-0c2e-4ba8-90e4-c646a898475d/95784170773.pdfIn PDF document text
    • https://4eb83289-b313-4542-b68c-79a1d4783db4.filesusr.com/ugd/f6336d_c6a1d608386648ef80a0dd7c2403068f.pdf?index=trueIn PDF document text
    • http://lakarovorur.epizy.com/keirsey_temperament_sorter_ii.pdfIn PDF document text
    • https://61249681-e2d1-4375-841a-b3723294d79c.filesusr.com/ugd/3d514e_2d5df547de96408ba936c41b0c3bfd5e.pdf?index=trueIn PDF document text
    • https://c5c1e25b-3ca9-4f8f-aecb-0ee3b29cb37b.filesusr.com/ugd/f4fe7b_6d0249a1298247e7865d5e0e7cc23315.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/425f9ec9-3cf1-4779-80b5-f9dfd6010120/58726297846.pdfIn PDF document text
    • https://5c2df1de-05ea-4e17-9aa3-38adc7ce3153.filesusr.com/ugd/ddd609_2ecd0d154f6c495ebd46c62b9fe3e32d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/423c3f1f-f432-4483-9544-685b927c25bc/62760376607.pdfIn PDF document text
    • http://mafefelanepule.epizy.com/pojulozavelem.pdfIn PDF document text
    • http://davidajepini.epizy.com/diary_of_a_wimpy_kid_the_long_haul_movie_trailer.pdfIn PDF document text
    • http://dudulexo.epizy.com/escala_hospitalaria_de_ansiedad_y_depresion.pdfIn PDF document text
    • http://fepesori.rf.gd/95542099884.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001832b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1832B 4956 bytes
SHA-256: 894e5968255f35675bc8c318895612de1c5ff3567422b9211b05b3fb7ed1c4df
font_01_sfnt_off000193f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x193F1 11456 bytes
SHA-256: fc939640e6e71462d4e2cd284b3b4471083e46250d249012ae48006582602b52
font_02_sfnt_off0001ba4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BA4E 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e