Malicious PDF — malware analysis report

Static analysis result for SHA-256 bac5e6b9676ab365…

MALICIOUS

PDF

77.1 KB Created: 2021-04-28 11:19:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: e743bbac4c21df8d032fafeb2c410450 SHA-1: dbe9f8b602fe49ae0eabc533a01dce81de59b0a3 SHA-256: bac5e6b9676ab36539fd22dfac40cce0eddb74b4056fac566b06701067707324
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, suggesting a link farm or SEO manipulation tactic. One prominent URL, 'https://pelibifir.ru/strik?utm_term=how+to+handle+stress+during+interview', is likely intended to redirect users to a malicious site. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

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://pelibifir.ru/strik?utm_term=how+to+handle+stress+during+interview PDF link annotation
    • http://jobware.pro/kutugilebosifupusoj7o01i.pdfIn PDF document text
    • http://masalev.ru/gospel_fluency_book_reviewjdhdb.pdfIn PDF document text
    • https://cdn.sqhk.co/mujejadalale/Pggdiif/15088294677.pdfIn PDF document text
    • http://goodsfor.life/margherita_flatbread_cheesecake_factory_caloriesgkwys.pdfIn PDF document text
    • http://idealslim-italiaoficial.site/kifagurelegex36ee.pdfIn PDF document text
    • https://cdn.sqhk.co/nepofigiper/ciakhcy/super_mario_nes_emulator_online.pdfIn PDF document text
    • http://ellmax-site.xyz/sakegotelipezito3d11d.pdfIn PDF document text
    • https://cdn.sqhk.co/jategumeb/wiij4gi/educational_coloring_pages.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/kitakilesa/learn_html_for_beginners_in_hindi.pdfIn PDF document text
    • https://e7f45dcf-1957-410e-85b1-216e85a225c4.filesusr.com/ugd/a2c2bc_d06543870dc846feacfc3542ed7580e6.pdf?index=trueIn PDF document text
    • https://033f1a72-e514-447f-b44b-9d234b37386c.filesusr.com/ugd/f05202_b91af322e9bb40a78e2e726ed9664973.pdf?index=trueIn PDF document text
    • https://a2c67b61-a01d-4053-b7ad-f1487bca8054.filesusr.com/ugd/24853a_89868e8824444520b006c8d37ebb48a1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/taturi/nikon_d5100_manual_video.pdfIn PDF document text
    • https://0feddc0e-03bc-46a3-a741-45303deff239.filesusr.com/ugd/6ea6a2_8eefcab821dd43819e7c3ca7a78a9bbc.pdf?index=trueIn PDF document text
    • https://9de673a2-3b8e-40eb-bbf5-c0ad8e71a3da.filesusr.com/ugd/bd5c68_43d19f9b68134651ac213174f67ec609.pdf?index=trueIn PDF document text
    • https://de99c131-68bf-4271-bcef-cda292486844.filesusr.com/ugd/f5892c_ccdffd64845c4227ad64d20d2ea90425.pdf?index=trueIn PDF document text
    • https://d8d691c7-cf48-432b-bece-a54604b57851.filesusr.com/ugd/1e3a4b_4dc5b42d2550438aaa62d4c2ddfe186e.pdf?index=trueIn PDF document text
    • https://22e365c6-0853-42e1-82f8-83473bf9c0bf.filesusr.com/ugd/217d68_bc72dba5de1a4b27a800ea5b69ef729a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kosipefojaw/kufumo.pdfIn PDF document text
    • https://9e2bb560-353e-4f5d-a08b-1363560edab4.filesusr.com/ugd/6c032c_3c1aa12b0ff241bf9b407b181916090d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jovekus/82017122329.pdfIn PDF document text
    • https://006b50d4-ad2a-4261-8279-34542eb0d7b0.filesusr.com/ugd/a640e9_973e5e76b4eb46f1b4641298dc8f88fe.pdf?index=trueIn 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_off0000f187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF187 5200 bytes
SHA-256: 497f5f25e8dda6149106e5ca38aff21dff6a81eada006060fb5bab3ca1fef352
font_01_sfnt_off00010344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10344 10336 bytes
SHA-256: 624d2bed78aafbaf04d41c573d3faf8694d777fe11f3d61912baa38651f2aa22