Malicious PDF — malware analysis report

Static analysis result for SHA-256 41baf9fb16b2b046…

MALICIOUS

PDF

70.0 KB Created: 2021-03-27 18:37:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: e987fa610daa10b1ebf51c427a228056 SHA-1: 958e8a6a0e33e5884f23509af56f4db9707616ae SHA-256: 41baf9fb16b2b0467ba45a065ac1fc13f867d1d2195b44f120dc2e2257c2e04f
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links to other PDF files hosted on various domains, many of which appear to be disposable. This behavior is indicative of a link farm, likely used for SEO manipulation or to distribute malicious content. The ClamAV detection and ML classifier further support its malicious nature, classifying it as Pdf.Phishing.Trojan. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://resalured.ru/award?keyword=business+mathematics+12+pdf PDF link annotation
    • https://bapoxipen.weebly.com/uploads/1/3/4/6/134684349/labafakawagawov.pdfIn PDF document text
    • https://sazalilo.weebly.com/uploads/1/3/4/5/134592982/julapozidadu_kujoraj_fibitunepuzip_kexuvudaw.pdfIn PDF document text
    • https://nurosamemozixa.weebly.com/uploads/1/3/4/3/134375837/1564569.pdfIn PDF document text
    • https://fipamexi.weebly.com/uploads/1/3/1/4/131407823/65783.pdfIn PDF document text
    • https://gepufefodu.weebly.com/uploads/1/3/4/0/134013389/f9f2384832c5.pdfIn PDF document text
    • https://pirowefe.weebly.com/uploads/1/3/4/4/134444143/f5a624c4bb4991.pdfIn PDF document text
    • https://ranazujip.weebly.com/uploads/1/3/5/3/135398887/nekaweweduxoti-rerorukox.pdfIn PDF document text
    • https://mirezavofuju.weebly.com/uploads/1/3/4/8/134870541/gasudekijajidetug.pdfIn PDF document text
    • https://gavuwexis.weebly.com/uploads/1/3/4/7/134772394/ea421.pdfIn PDF document text
    • https://jorokepevi.weebly.com/uploads/1/3/4/6/134688072/sefamatewo-fibanonen-vevodeketuzaxo.pdfIn PDF document text
    • https://sufosuzupunu.weebly.com/uploads/1/3/1/3/131379650/vuguberuke-vibesubevibax-lebes.pdfIn PDF document text
    • https://desaviguwogo.weebly.com/uploads/1/3/1/8/131871994/802c96609.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9f9bd9fa-00fe-4673-b34e-9a629881f524.filesusr.com/ugd/09273f_387a3334e2344725b8faf24eebcabe63.pdf?index=trueIn PDF document text
    • https://7fe6b731-3703-45da-bcbe-faf39b4d3392.filesusr.com/ugd/880a7e_4865b2e3ae264915870bd488e4ff1a1a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/75cdf1dd-d3fb-4fa4-ba0a-d54888577040/6694539219.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3fd481a7-8439-43b7-a710-cc4a6b47c49e/83593046414.pdfIn PDF document text
    • https://d52369c8-37f2-40d9-9d5f-d682b3b4a2e4.filesusr.com/ugd/6d5a7b_4b3a90017808454abdfb53e7525d0d5a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f6bc3f8e-7fca-4cb2-8d57-ffb26b7107b0/what_is_the_primary_objective_of_canadian_healthcare_policy.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5cd98fd2-e268-4959-b4fb-b7a771f729e7/what_to_use_kitchenaid_mixer_attachments_for.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14905e9a-fd9c-4990-a0fb-dd8ca0b55149/learn_bengali_through_english_in_30_days_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6fd9b8ea-41b7-47d5-ae1e-1e739adb1e02/93389989785.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f332877e-d9de-4fd0-868c-64b09a871e90/dunaloxizutat.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_off0000d2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F0 5500 bytes
SHA-256: a2c5050777bef67254066581f144ae8a125a906c2dd2a85d5e29379f2160ac68
font_01_sfnt_off0000e590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE590 10820 bytes
SHA-256: 23f7b872b7ed19f7a499fc836ce43d2b73305e22237026a8b41ee79c422ba643