Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad66e360e53ea312…

MALICIOUS

PDF

86.6 KB Created: 2021-05-13 16:44:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 2a3b84d8a9c23248e6b4dadeb5541fc9 SHA-1: c464c012325d74392d66b5be52ef3244fb307f72 SHA-256: ad66e360e53ea3128e468325eb927063681015a8b072d159f8de22bd62a2b1b8
66 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many pointing to disposable hosting, and is flagged by a machine learning classifier as malicious. The document body, though heavily corrupted, appears to be a lure related to child development, likely intended to trick users into visiting the malicious domain 'kuzutuzo.ru'. The presence of embedded URLs and the nature of the heuristics suggest this file is part of a phishing campaign aiming to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 4

  • 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://kuzutuzo.ru/strik?utm_term=how+children%2527s+thinking+and+learning+develop PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4479470/normal_603ed0753fe3d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378390/normal_5ffbfd8e17f89.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414352/normal_603a2e40f04ae.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402533/normal_606622959c9bb.pdfIn PDF document text
    • https://zaderoxuk.weebly.com/uploads/1/3/4/6/134694825/xixotefasolezad_pusodibufofom_zigifu.pdfIn PDF document text
    • https://kudiwugeditonaf.weebly.com/uploads/1/3/5/9/135964520/lewos-geliba.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368996/normal_5fe3d7dee163f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473645/normal_5ff1101e37e7f.pdfIn PDF document text
    • https://wezenazuzive.weebly.com/uploads/1/3/4/7/134764498/misifaravugapolax.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393916/normal_5ff69a4249543.pdfIn PDF document text
    • https://sikenobavusemel.weebly.com/uploads/1/3/2/6/132682861/tugemunuwuziz.pdfIn PDF document text
    • https://xemavuvewo.weebly.com/uploads/1/3/5/3/135394060/1635841.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/8e5cf2ca-7a2a-4e0a-ba11-83147e8a3e31/tuvepiwotutusukefud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9fb7bdd-8929-4d9b-8cf4-4b0fddd96bf8/9192136958.pdfIn PDF document text
    • https://9b56c271-8e60-4ff0-96d1-8930f8c082f8.filesusr.com/ugd/5a1ab0_fdfcc93866f34cef884c4d1c007702c5.pdf?index=trueIn PDF document text
    • https://d692b82a-d563-45ba-818c-0512d98079dc.filesusr.com/ugd/1c7397_0b855af9caed4387a1d9a940c05d0dde.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/17fcacbb-1444-433c-9fc6-084c65b4593a/tutoxojavame.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ad4c9401-4539-464d-a924-830877211130/how_to_make_origami_butterfly_step_by_step_with_pictures.pdfIn PDF document text
    • https://s3.amazonaws.com/zatasipezeg/pewoli.pdfIn PDF document text
    • https://s3.amazonaws.com/vofadoloves/report_card_comments_for_3rd_grade_reading.pdfIn PDF document text
    • https://s3.amazonaws.com/muwomapotumugi/vazewuwawoman.pdfIn PDF document text
    • https://s3.amazonaws.com/mipeboro/biostatistical_analysis_4th_edition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/157f7731-a874-424b-b561-b21a77d24654/mrs_dalloway_book.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_off0001041f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041F 5332 bytes
SHA-256: f98f491ea4be03096cbc3486e7e775ae61c04726ef163d2933c033434014fb11
font_01_sfnt_off0001164e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1164E 11324 bytes
SHA-256: 88544f20440176216b14c6598fa6b8bc6b3198b0e241cfbf970fdf1cc12f062d
font_02_sfnt_off00013cca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CCA 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3