Malicious PDF — malware analysis report

Static analysis result for SHA-256 520c7f91ed75b4ac…

MALICIOUS

PDF

71.1 KB Created: 2021-05-10 02:37:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 1d026a887a438bfb560e4981d7bbef7f SHA-1: a594675a2b9e541f3f52c83100a337354548c6e9 SHA-256: 520c7f91ed75b4ac5898917966a0bbd7957a7df41fa413d112e6e008fcebb873
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable domains, suggesting a link farm or SEO spam campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://nipisod.ru/strik?utm_term=ti-84+plus+graphing+calculator+battery+cover PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4365591/normal_601904fed4bee.pdfIn PDF document text
    • http://usersdeviceprotectionservice.site/relevance_of_axiology_to_educationjicd2.pdfIn PDF document text
    • https://lajexupizad.weebly.com/uploads/1/3/0/7/130775806/3000094.pdfIn PDF document text
    • http://xujadawowupu.scienceontheweb.net/new_cutting_edge_intermediate_student_s_book.pdfIn PDF document text
    • http://qlemelest.online/570365329714b1vy.pdfIn PDF document text
    • http://hookup753.fun/pete_the_cat_thanksgiving_activities563pm.pdfIn PDF document text
    • http://obschee.xyz/lg_inverter_air_conditioner_error_codes_a108qkz.pdfIn PDF document text
    • https://tonibakak.weebly.com/uploads/1/3/5/3/135346506/7872553.pdfIn PDF document text
    • http://kodepovorivapi.mygamesonline.org/79679613974.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385869/normal_6060afd7e1ac4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500877/normal_6032cccb871d7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6d251753-49d0-4f5b-a278-10ed1cacc9d0.filesusr.com/ugd/5c139a_05e289c7064b4da895c94217bdbaa2a4.pdf?index=trueIn PDF document text
    • https://eb9d0a7c-f241-4274-9260-18def620c3fd.filesusr.com/ugd/796b85_5f2e828803c74e9191406e7a2f40c462.pdf?index=trueIn PDF document text
    • https://203aa715-7352-46b1-b16b-5d0aeeaa27a2.filesusr.com/ugd/0582e0_a75267ff095046a1a8e312cf62092d75.pdf?index=trueIn PDF document text
    • https://3012fa3b-51b7-4264-898e-e15d6fab1eb1.filesusr.com/ugd/ee5524_460f1c4615814d22a070ee1788982e01.pdf?index=trueIn PDF document text
    • https://2a4065d7-883d-43e8-a524-7ce9aa4b4e88.filesusr.com/ugd/ccb1c6_12461bf4015646bfbfd7c17aad68a201.pdf?index=trueIn PDF document text
    • https://d0bf7e8b-5449-41c0-93e9-161603c0719f.filesusr.com/ugd/197ed4_a2eb6ac868204acc9a6b7413edccba4c.pdf?index=trueIn PDF document text
    • http://mifedisiso.atwebpages.com/behavioural_theory.pdfIn PDF document text
    • https://a121017b-3fb3-450c-9156-48dd71a9bf80.filesusr.com/ugd/07625c_1bc7c6108c1a42659297d3c0c47d7f1d.pdf?index=trueIn PDF document text
    • https://5c71d6b4-13b5-43a2-97a4-9a0eba4d0f4d.filesusr.com/ugd/0f1814_80c739ebe6c54c879b214382c17ccaab.pdf?index=trueIn PDF document text
    • http://fotizojorirepel.onlinewebshop.net/hepatitis_c_virus_transmission.pdfIn PDF document text
    • http://suvalomimo.atwebpages.com/23999360625.pdfIn PDF document text
    • https://e57d8632-f742-4524-ada6-9cdf759d9f13.filesusr.com/ugd/b0cb2d_3766387db2f74553a5f4e37d92d77be6.pdf?index=trueIn 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_off0000d2d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2D1 5760 bytes
SHA-256: 788a638196745edaecf84afd9248c3592dbbdf6405aca68a0d94d83bf031a389
font_01_sfnt_off0000e67f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67F 11252 bytes
SHA-256: f201c8c838a0ee4c191a8231e78a2eb8971507e968a3768692d08d86a131e12b