Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4ef9c6013db7a9e…

MALICIOUS

PDF

82.5 KB Created: 2021-04-25 07:16:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4ec37c1df0cab5e078f85e3c86e21f21 SHA-1: cf7f3dad92fb6c5c8893bbdfd168cea0f58cb4bc SHA-256: c4ef9c6013db7a9e722aaf66162f0a94fe96eae77372bfa4ee732020741c9b69
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to a suspicious domain ('kuzutuzo.ru') that is likely used for phishing or to serve a second-stage payload. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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 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/strik?utm_term=chef%2527s+choice+knife+sharpener+120+instructions PDF link annotation
    • https://cdn.sqhk.co/pubamegumox/yiijagd/dudogudufaralimifipove.pdfIn PDF document text
    • https://cdn.sqhk.co/dakizenewa/gfcOyjh/babitipevovanufoj.pdfIn PDF document text
    • http://judupebe.getenjoyment.net/eicar_test.pdfIn PDF document text
    • http://pokezokebawi.mygamesonline.org/altivar_320_manual.pdfIn PDF document text
    • https://cdn.sqhk.co/jisaside/ORghrjd/red_tone_neutralizer_shampoo.pdfIn PDF document text
    • https://cdn.sqhk.co/sawitofi/LFrjejc/58828362716.pdfIn PDF document text
    • https://cdn.sqhk.co/mipijotom/xiijfSa/6169031073.pdfIn PDF document text
    • http://zizivumagove.iblogger.org/36176744343.pdfIn PDF document text
    • http://nipawifaxupus.mygamesonline.org/mupexepawovomubesigiw.pdfIn PDF document text
    • http://pakunobun.getenjoyment.net/sports_awards_2020_download.pdfIn PDF document text
    • https://cdn.sqhk.co/pekotegafod/hYjezgj/97226792886.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://uploads.strikinglycdn.com/files/46eaf04f-4423-4532-9790-49a6c47cf4a4/liwojewixapigunibokezo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5603042f-068f-424c-a4fd-e5cb46592375/xakuzifofuxafurudifafefaj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c66d6976-d390-48d3-a099-c165e76ccb1a/california_cooperage_hot_tub_model_380_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90dc78a0-0b24-464c-bc03-d4489cf1076c/pajareletatusana.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6ece410-9fe2-4ee8-b338-f7a2fe6e9963/how_do_i_replace_the_batteries_in_my_xfinity_remote_control.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/048f6a19-cdeb-42fb-ac00-e630f54b5307/handbook_to_higher_consciousness_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f82f1bb7-a707-45e2-a786-4cf45240e982/sunbeam_space_heater_amazon.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32eca74e-225e-458a-84c9-c1d5ae1ee36a/12976543273.pdfIn PDF document text
    • http://xamojivegubon.epizy.com/java_web_service_soap_client_example.pdfIn PDF document text
    • http://gifagedopodub.epizy.com/what_are_the_different_types_of_cochlear_implants.pdfIn PDF document text
    • http://megugasawixige.onlinewebshop.net/numbers_in_spanish_exercises.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B9 5400 bytes
SHA-256: 10cb04bdc70ce5942fa2fd6969fb13dcf1f7b68963d7b8c32c47bb369433cb9c
font_01_sfnt_off00010916.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10916 10804 bytes
SHA-256: 460ee813fa6057ebf3c974cf05c582eb7ef612b9b1e56d2548667586a88aa0ec
font_02_sfnt_off00012dd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD5 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34