Malicious PDF — malware analysis report

Static analysis result for SHA-256 6961fc61f45e497a…

MALICIOUS

PDF

78.8 KB Created: 2021-04-10 12:23:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: a989b14fbe7d5a7815a64c9c585017e2 SHA-1: 25ca7eb82d08234355dbfbb1ec408072379a46dd SHA-256: 6961fc61f45e497a6006b309f1e731c1c2efe840b7b669f9f71e60273cf4d2a1
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm used for SEO manipulation or to distribute malicious content. The primary IOC is the suspicious domain 'midufefew.ru' which is part of the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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://midufefew.ru/strik?utm_term=the+little+dictionary+of+fashion PDF link annotation
    • https://cdn.sqhk.co/luwivimexu/Biyhbig/xulazi.pdfIn PDF document text
    • https://cdn.sqhk.co/kajurineg/yzNhhcX/carnival_games_switch_gameplay.pdfIn PDF document text
    • https://cdn.sqhk.co/xuxozowaki/mLrMuig/climbing_trails_in_colorado_springs_with_waterfalls.pdfIn PDF document text
    • https://cdn.sqhk.co/nufuwijili/hdCid14/gojanebamumidi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414689/normal_5fccb3659b5cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480399/normal_6017176e42e90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458417/normal_6031d6a0697fa.pdfIn PDF document text
    • https://cdn.sqhk.co/nobipajami/chfEegf/dwts_judges_comments.pdfIn PDF document text
    • http://itgermany.net/hp_officejet_5740_not_printing_black_inkawnb8.pdfIn PDF document text
    • https://cdn.sqhk.co/lerapuraroke/iegjjbd/mod_game_lord_of_estera.pdfIn PDF document text
    • https://cdn.sqhk.co/tedalome/jcO5mgg/cyber_dead_premium_modern_run_and_gun_gameplay.pdfIn PDF document text
    • https://cdn.sqhk.co/xexodaxafu/Fiahd1i/zugutosigana.pdfIn PDF document text
    • https://cdn.sqhk.co/pujapipiwat/76a5ian/22444553300.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484835/normal_60285ab9874c0.pdfIn PDF document text
    • http://ersoil.fun/isotope_notation_worksheet_2_answerssi6bg.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454426/normal_605815269fa23.pdfIn PDF document text
    • http://igcopyrightclient.com/lalomubepaterojivksgcj.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/3dcec4dd-e7f2-485d-9475-c31f65b224a3/how_to_pair_insignia_remote.pdfIn PDF document text
    • https://6bfd3344-23d3-4e03-ab7d-00c1c23eecf6.filesusr.com/ugd/be19e1_3f3fe32c521c49dc94e9a3dbd18b360f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/530d5e43-160e-4ca9-97ce-4229022ad421/hit_the_glass_wall_definition.pdfIn PDF document text
    • https://6363ce23-9394-4102-a476-7be320345719.filesusr.com/ugd/7c41c1_d3ecd15890c44d798c18157aee690ea7.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c4de96d-17c7-41d3-a0e1-5eb5edac8d40/how_to_study_for_aswb_exam.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/612ea203-7555-4c33-bc87-ef1315b565af/wafatalugezunafoju.pdfIn PDF document text
    • https://aca292c6-a3ee-4c96-b4c9-db15c8eca1b9.filesusr.com/ugd/cd1d52_9ad5b22b93ae473ebe70e793c4989154.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c9240c04-c104-446f-bbec-f6ef55416f15/bivowakit.pdfIn PDF document text
    • https://c93ae04b-3d95-4128-ac62-0503c91a26e1.filesusr.com/ugd/002f5e_6faaa5d765d14f3fb0cd272af16d3ea5.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_off0000f8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E3 5160 bytes
SHA-256: 33a5b98684a5ba5dec40625902d0c1af8f57549366cab1544eeeea78948b5254
font_01_sfnt_off00010a71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A71 10380 bytes
SHA-256: 22ec53b1d1fc72ee0d1fb7700bf0af095cdd98de303ab5f89ea7a600a20ce319