Malicious PDF — malware analysis report

Static analysis result for SHA-256 81724f4710fb14cd…

MALICIOUS

PDF

83.3 KB Created: 2021-03-18 18:46:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 34a5c3f739089eb521534fcf0bbfb78a SHA-1: f4168d3068ed5793dfbfcfc465d8c1baf0feadfd SHA-256: 81724f4710fb14cd5d14a2b825b3a71af9f5a757538f39390ad6bf9940f7b453
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, with a critical heuristic firing for a 'PDF_SEO_LINK_FARM'. One of the primary external URIs points to 'vilenefex.ru', which is marked as unknown reputation. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the structure suggests it's designed to lead users to malicious content, likely via a phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://vilenefex.ru/wix?keyword=shadows+in+flight+orson+scott+card+pdf PDF link annotation
    • http://xuzobinemipivor.mygamesonline.org/guxuvemi.pdfIn PDF document text
    • http://gewusoluxul.scienceontheweb.net/how_to_connect_ps4_gold_headset_to_android.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/2f62ff6f-ffac-44a6-983d-ae77c26c165c/38635629288.pdfIn PDF document text
    • https://s3.amazonaws.com/suzujewa/vadulokiruvumejovidodixe.pdfIn PDF document text
    • https://13a7c488-548c-4b48-b567-d2b0b9a3e1de.filesusr.com/ugd/85d67f_6069c227b37e4d85a551ffbeaba84604.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jebokizez/clear_google_search_history_on_android.pdfIn PDF document text
    • https://587b455d-cc79-4428-8e80-a8b75ce23bca.filesusr.com/ugd/021ec8_6452d7ccf3424ac1b6ad855b4b335965.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a4a6cf91-792c-4135-b323-a3eadab06636/tintin_books_ranked.pdfIn PDF document text
    • https://923a8ca3-316b-4844-b38f-9bc955ad4852.filesusr.com/ugd/312e0e_8a1f48b2cc5646f08d75354e3fb78ad9.pdf?index=trueIn PDF document text
    • https://5057b38b-f250-4925-a5fd-2dbc054a2c1f.filesusr.com/ugd/25ee37_b9c8d04a206a44a3b8b78585514898b2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/80bb7ae4-db27-400c-b4b0-4fd30a9fddff/zovixowetilisezaze.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/99625db7-fdd1-4737-9a22-570d37b33cf3/what_does_the_term_boundary_condition_mean.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea4c7f69-44a1-4120-add5-07ae584a3910/45001126759.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1bdd3bd5-28aa-4953-bc22-4365759582a0/less_than_zero_movie_remake.pdfIn PDF document text
    • https://329f26c8-0235-4118-8622-173d264d9cf1.filesusr.com/ugd/221f3a_5ac22b21d1634d52b1dfc641143f495e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/topipovikapari/new_love_music_ringtones.pdfIn PDF document text
    • https://8c285b57-3156-47ce-881b-df665acc117b.filesusr.com/ugd/8d46c2_2a7032fa91244b11b4f7d5312c7c5df5.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bubeto/australia_marine_radio_frequencies.pdfIn PDF document text
    • https://907864b8-ab38-4b43-b195-7646ee37c451.filesusr.com/ugd/c4b402_897b1758eb5543878f5973df165db4a5.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zaxawetawupo/44795162548.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/452943fa-89e9-4021-8271-69f703a15b38/92368297433.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/80326e36-ce53-46ca-b2dd-e416ffa44354/how_do_you_flush_a_rheem_tankless_water_heater.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_off0000f973.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF973 5284 bytes
SHA-256: a60aac4661812b40bfbd350efe47a54dd9a762cbea036e8805ead2759ce742ae
font_01_sfnt_off00010b62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B62 10676 bytes
SHA-256: ad892f351c523b11fa18999f7d75ba1294792713d537cde8430eb0da8fb1358a
font_02_sfnt_off00012fd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FD9 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176