Malicious PDF — malware analysis report

Static analysis result for SHA-256 28b5c4916931142b…

MALICIOUS

PDF

79.1 KB Created: 2021-04-11 21:40:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ac116a433449e9f82bec98aa6e0f3113 SHA-1: 5520b2d676b726549c87070f7292fb1f7a7ca6cf SHA-256: 28b5c4916931142b129eca9765ff7b19ff640026028aff50e13e55c42818baa0
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, with one prominent URL pointing to a suspicious domain, likely intended to trick the user into downloading further malware or visiting a phishing site. The PDF's structure and embedded links suggest a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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 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://jumiwimov.ru/strik?utm_term=ravpower+filehub+travel+router+ac750+manual PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4408878/normal_60491b5b4553f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491927/normal_606c83522d939.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490244/normal_600fe971c656e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445119/normal_602b27874d153.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467298/normal_5ff3690d0171b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382974/normal_602483deba924.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488335/normal_604a16bdac39f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383156/normal_5fd9bfffe32c7.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/2b2fc834-376d-48dd-97b6-c42cdde2a7d3/vululizat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01ca6cef-6560-438a-bca5-720e73f79efd/77447814382.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b739cfd4-50a7-4f77-85dd-c07b8818a459/batuwofefe.pdfIn PDF document text
    • http://sivutesafukim.rf.gd/what_are_the_hardware_and_software_components_of_a_computer_network.pdfIn PDF document text
    • http://wezexezawudev.rf.gd/gimivugozaguradeno.pdfIn PDF document text
    • http://nisoruv.rf.gd/57895910941.pdfIn PDF document text
    • http://paxomutu.rf.gd/linux_admin_interview_questions_and_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93e801c1-e210-4d7c-87cd-8333562004d4/debubopukuxo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/540ebdce-6f3f-476a-b225-3499b996e985/hamilton_beach_countertop_oven_with_convection_and_rotisserie_31100.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4551f08-8405-4ef3-a4b0-d58947c81119/liftmaster_8550_error_code_4-3.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6406cfe-ad23-4fbe-9c37-923c5add0809/kimusiv.pdfIn PDF document text
    • http://podadoperis.rf.gd/laboratory_safety_precautions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e44c1934-3f3d-4fbd-85e5-0bdd6bd4095f/sennheiser_rs_175_review.pdfIn PDF document text
    • http://nojudadosuzaxi.rf.gd/propiedades_nutricionales_de_los_arandanos.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_off0000f697.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF697 5724 bytes
SHA-256: cb83ce1a2a4e26147f02a13be5e37c61d170a81e9b098846eece45057ac6986a
font_01_sfnt_off00010a10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A10 10796 bytes
SHA-256: efd63755a9b55363dbc385fc86ff9288591d02ba693697b2370f51d3296569a4