Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c1d82826fbfa44b…

MALICIOUS

PDF

79.0 KB Created: 2021-03-08 02:39:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 189d092d12456174f283638ea374048f SHA-1: 97888c6191057a2018afb031b0d719130d1de30d SHA-256: 4c1d82826fbfa44b29db9b7f8d1228b0e86b0d41127d1f26ce7ced5a682e9bdd
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous external URIs, with a primary suspicious URL pointing to 'kuzutuzo.ru'. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially harmful content, possibly for phishing or SEO spam.

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://kuzutuzo.ru/award?keyword=how+big+is+a+giant+sub+at+jersey+mike%2527s PDF link annotation
    • https://cdn.sqhk.co/fupokonabat/gjcijYX/26335093207.pdfIn PDF document text
    • http://bigwin-1xbet.fun/roomba_780_manual_danskzk871.pdfIn PDF document text
    • http://alania365.ru/pesadav8o3b.pdfIn PDF document text
    • http://netlysy.online/emulator_for_android_games_on_pc18zm6.pdfIn PDF document text
    • https://cdn.sqhk.co/kominepoli/Xhjlhgj/gazokuru.pdfIn PDF document text
    • https://cdn.sqhk.co/xivomojuf/jceBhd8/startup_kdrama_cast_han_ji_pyeong_young.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://c36efdde-2309-4ce2-a10d-b6df2ce12cd8.filesusr.com/ugd/e98059_e1b397543dc5449a8ce57c376b3d7c9f.pdf?index=trueIn PDF document text
    • https://53002a68-e35f-4167-ac88-1ab9777d7e72.filesusr.com/ugd/f5bc2a_43e862fc61c941dd8008ced67917e3e6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/satedafadusizo/nbi_online_application_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0ad6fd1-2070-4420-a335-39602483535b/harry_potter_and_the_half_blood_prince_movie_ending.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/56529db4-eebe-4873-8796-aaece18ceddb/tegogusegamusulab.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/58e93562-cf7e-4189-a2c0-d17132de6aa5/make_your_own_home_screen_app.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5697da96-3b92-45e5-943a-7a282803e08d/how_to_start_a_rebuttal_in_a_debate.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/92f00002-3b84-4229-8a33-b03f0812a852/can_windwalker_monks_use_polearms.pdfIn PDF document text
    • https://92e0cadd-ca3c-497d-ba7d-1aece6ee6da0.filesusr.com/ugd/008e52_4ff67a51095648b6bf0fa27a03f78866.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9784cde5-88ef-41d3-ac43-0a55a49bb078/nikon_coolpix_p510_camera_wont_turn_on.pdfIn PDF document text
    • https://fb79ad55-22b5-4823-9538-35c71bbbd514.filesusr.com/ugd/ea423f_326c86c995f845bd8e09963fd3dbccea.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xewamejixolefaj/kijivejo.pdfIn PDF document text
    • https://ab60d57a-1f92-408f-9079-0b325776b613.filesusr.com/ugd/724fb5_afc27b9485a34aff8a9cd238f8f446cc.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA40 5324 bytes
SHA-256: b678a571aeee4823a6cbb448c2d3609b92574de7d915ec191dfcc4a55d2e4883
font_01_sfnt_off0000fc63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC63 10412 bytes
SHA-256: dbcf2e113ea0ceabb0edd2a9c352f9d59aab96b1bd5f647aaa0cf4ceb9a63948
font_02_sfnt_off00012012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12012 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230