Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c1ef609bb56f6cc…

MALICIOUS

PDF

76.3 KB Created: 2021-05-25 12:46:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b9fa6a9872d8269008630b8f94b270dc SHA-1: 67ba40a9721308dec0026d3da0dba459f825a894 SHA-256: 4c1ef609bb56f6cc8cf10e98133ceb0c0bb2b7dbbeb5b47e431503eb92c6ec60
186 Risk Score

Malware Insights

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

This PDF file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external URIs, with a primary suspicious URL being zajinet.ru. The presence of many links, some hosted on disposable domains, suggests an attempt to manipulate search engine results or redirect users to potentially harmful content. No scripts were extracted, but the PDF structure itself is used to facilitate the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zajinet.ru/strik?utm_term=oddbods+turbo+run+mod+apk+1.0+0 PDF link annotation
    • https://nuniladolu.weebly.com/uploads/1/3/0/7/130775245/bamov.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470543/normal_5fd6daf0b962b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476783/normal_5fd0e41eec7e7.pdfIn PDF document text
    • https://zogerosolubelu.weebly.com/uploads/1/3/4/5/134576434/lovuf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467561/normal_5fe90b6d39413.pdfIn PDF document text
    • https://molavose.weebly.com/uploads/1/3/5/3/135350427/gotokuvuzitusitazib.pdfIn PDF document text
    • https://lapolepep.weebly.com/uploads/1/3/1/4/131406498/gofilizer_bujupoxib_gonajefuxem_garimodogudege.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416787/normal_5ff69722ed98e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375705/normal_5fe070fcd5a8b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416928/normal_5ffa3319748d3.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/mejifavo/gokukone.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b59774c-4c58-4b0c-991a-25a2a134d6b7/bofolilupapodaded.pdfIn PDF document text
    • https://s3.amazonaws.com/wujanozo/dawobifatugitorabokon.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5a91282-1874-42d6-a094-03744c290848/maytag_neptune_washer_control_panel_not_working.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd57d936-db93-417a-8be5-34122dc701a3/free_download_tamil_bible_concordance_format.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66656f6f-bf2d-4765-9cf9-ac4aa40288d4/geometry_angle_relationships_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4807c08a-987d-4f6d-9bca-b353b140d998/witcher_3_the_last_wish_boat_stuck.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4fcb0796-a85e-4817-9dfd-556683592466/fixurifuwibuwixasixo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd381070-2369-4289-9b64-96e268817a52/fodmap_foods_to_avoid_australia.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_off0000eb08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB08 5528 bytes
SHA-256: 14e1eca836d49349e7877368c351469e56617165fee6607c25dadec2c93b40cf
font_01_sfnt_off0000fdb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB4 11344 bytes
SHA-256: e19edf4a85dfb132ca952f6dd0604ee55b30799957925b4db429c2d36b31e396