Malicious PDF — malware analysis report

Static analysis result for SHA-256 bff55a5349503353…

MALICIOUS

PDF

78.5 KB Created: 2021-03-15 21:23:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 83be53b383b1c5956b7a94dcf52098d5 SHA-1: 1384bcf85601597ea3f8abfc3abb68adf11675d7 SHA-256: bff55a534950335319bc595664d346c5371a9a5d7943c8ca0e93777ed459dda2
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://midufefew.ru/strik?utm_term=best+way+to+learn+currency+exchange+calculator PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4374178/normal_603fa87d81893.pdfIn PDF document text
    • http://judanit.iblogger.org/cuanto_equivale_100_m_en_pies.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490365/normal_604e104d5e10a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366004/normal_6026fd1c13726.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://witigunakejawi.rf.gd/kobilaramu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96964f7d-d560-4ffe-9660-0390200919ba/how_to_score_fear_of_intimacy_scale.pdfIn PDF document text
    • http://nipanalex.epizy.com/a_level_chemistry_organic_synthesis_notes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a0a4be8-4882-48c5-b088-b1d2008661ef/first_aid_cpr_book_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/461bb201-1cf9-442d-a200-28888886c1da/jakifujipon.pdfIn PDF document text
    • https://ed4d48c2-14ea-47f5-a89a-b82193587323.filesusr.com/ugd/8ce377_dcf7ac84534c4328b07d703423d5a565.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9adb6d7a-effc-4f60-bfeb-2a8424974677/john_deere_42_inch_snowblower_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ac5e85c8-c902-4633-93ec-54bd5098006c/how_to_write_summary_for_a_resume.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0d083ba-4293-4d10-b57d-11b7be65ed99/.pdfIn PDF document text
    • http://fonaxipovun.epizy.com/loladipujatiredeteri.pdfIn PDF document text
    • https://fb4bdcd3-28a3-4206-a6c3-fb267f511c23.filesusr.com/ugd/0ad562_2023859f61fe436fbc1b48811df3def1.pdf?index=trueIn PDF document text
    • http://vinagojum.rf.gd/academic_phrasebank_navigable_2020.pdfIn PDF document text
    • https://39c1d623-eccb-4af0-a86a-15328a2d61f9.filesusr.com/ugd/3cb6cb_d26ea6fd967a4014b8b3934d5e4e2660.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/75303d95-5905-46e7-9d1b-26b9bf438732/womugidalomepagub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ab29492-481e-43ac-ba9b-7b64374cb022/describe_database_management_system_dbms_fundamentals_particularly_during_the_design_phase.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_off0000f4a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A3 5372 bytes
SHA-256: 55de9cb75b21bf6c103bf6ceef4c59cfaa16341625f2979b86e00050aaea9aa7
font_01_sfnt_off00010709.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10709 11044 bytes
SHA-256: e71a2974023f7c0fea8f3ae05ac0cb01ae173e0decb7edee5ebdf96469fc273c