Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c5e1be1a7382e15…

MALICIOUS

PDF

77.6 KB Created: 2021-04-01 17:26:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 45529f6c33e3c328feaafa14fae555e3 SHA-1: c58881d4ffd60a8c79e44e4cac3c2c46f155f4ba SHA-256: 4c5e1be1a7382e15c6a3e10e0df146e0ce85796f7567b5285261894232a9f473
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm or phishing operation. The document body, though heavily obfuscated, appears to be a lure related to 'hydraulics worksheet answers', aiming to trick users into visiting the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://zajinet.ru/wix?keyword=modern+marvels+hydraulics+worksheet+answers PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4368488/normal_5fe0659991f39.pdfIn PDF document text
    • https://povemiloten.weebly.com/uploads/1/3/4/6/134608376/dujejimavijive-jomedutavidufe.pdfIn PDF document text
    • http://mitisavad.getenjoyment.net/what_makes_a_good_team_player_interview_question.pdfIn PDF document text
    • https://vakupakofusiwu.weebly.com/uploads/1/3/5/3/135399484/sokum.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476757/normal_6033eebc7279c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451929/normal_6004ea13639a6.pdfIn PDF document text
    • https://nemapawa.weebly.com/uploads/1/3/0/9/130969411/retoguxebax_lezuxegip_vorabugog_nawapeba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487381/normal_5fd3453a9b082.pdfIn PDF document text
    • https://gejekawuxo.weebly.com/uploads/1/3/4/4/134497426/liwipex.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460241/normal_5fc659112372a.pdfIn PDF document text
    • https://kipigifusulip.weebly.com/uploads/1/3/4/4/134437712/nadejijapabapapebope.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/0eac60ca-f1a6-4815-a943-959398f3af15/how_to_use_samurai_sword.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4e79610d-1387-4338-a01f-e54f99b56ce9/poem_woman_work_by_maya_angelou_questions_answers.pdfIn PDF document text
    • http://merovuditipin.onlinewebshop.net/dr_jekyll_and_mr_hyde_1931_full_movie.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1bc34b62-4150-42a2-816c-3a1f0ba82e62/roku_xd_2050x.pdfIn PDF document text
    • https://s3.amazonaws.com/nimuwet/kiwagixisesazemesod.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f62df20e-45fe-48f9-aaa5-80ecbfd7d276/sixunubukapi.pdfIn PDF document text
    • https://s3.amazonaws.com/dogazisuze/nexegomenesafuloladupa.pdfIn PDF document text
    • https://s3.amazonaws.com/wazotojemov/dawuwafaketevavipani.pdfIn PDF document text
    • https://s3.amazonaws.com/kovilowab/6688274402.pdfIn PDF document text
    • https://s3.amazonaws.com/rogugagatuf/autocad_electrical_library_dwg_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0278a85f-b1ed-4bde-9efa-581c1e59be23/xawasa.pdfIn PDF document text
    • https://s3.amazonaws.com/zibenoroduzuw/video_from_vimeo_online_free.pdfIn PDF document text
    • https://s3.amazonaws.com/tutasujal/la_iliada_caracteristicas_de_los_personajes.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_off0000ef25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF25 5504 bytes
SHA-256: 1d14f362fc28bfea5c74f1a6262f4f761390207e9f1abcd10ea380e081ffc158
font_01_sfnt_off000101d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101D2 11460 bytes
SHA-256: 3b9de8e95a4d125dc92521e5d0f2c604b971e6c9c73e1733b23158999dbcc2b0