Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dcb719e50c0936c…

MALICIOUS

PDF

75.0 KB Created: 2021-04-08 17:40:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 23bf133d868d284b062d7a0234338009 SHA-1: 6dbe80fecf11bde20de0fd5f40fc3e6d94b7e9e1 SHA-256: 4dcb719e50c0936c0c2ab85fa7619365d3f45ff067899f15252c13822f3ed0b7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jacksth.ru/strik?utm_term=design+of+reinforced+concrete+and+brick+masonry+structures+anna+university+question+paper PDF link annotation
    • http://fajesamosini.sportsontheweb.net/93904990150.pdfIn PDF document text
    • http://znalomstvavip.site/galvanised_steel_corrugated_sheeting2zca5.pdfIn PDF document text
    • https://lelewubinuzuton.weebly.com/uploads/1/3/4/7/134771703/nabetiz.pdfIn PDF document text
    • http://swiss-family.space/woxedonovatimonexibodes60zac.pdfIn PDF document text
    • http://jumbochecker.com/honda_ex650_generator_air_filterpwwsh.pdfIn PDF document text
    • http://salonop.xyz/87877765359bfrn8.pdfIn PDF document text
    • https://rerutafedebe.weebly.com/uploads/1/3/2/8/132815298/1986005.pdfIn PDF document text
    • https://mejatuwunuzawe.weebly.com/uploads/1/3/0/7/130775850/noguvezawatevi.pdfIn PDF document text
    • http://keniworu.mywebcommunity.org/fuvesekewutafogujaw.pdfIn PDF document text
    • https://wenuzivubog.weebly.com/uploads/1/3/5/3/135392435/xufederaxo_soxalogulox.pdfIn PDF document text
    • http://dabosesavedevet.medianewsonline.com/29197213689.pdfIn PDF document text
    • http://7lessons.fun/nixon_the_unit_407jxt7.pdfIn PDF document text
    • http://zatutajijiti.getenjoyment.net/what_is_dental_caries.pdfIn PDF document text
    • http://e-devletodeme.net/tuzopudomiluxd6h66.pdfIn PDF document text
    • http://lnstagramcopyrightcenter.com/how_many_calories_in_subway_multigrain_breadrhcas.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pekamidakoj.atwebpages.com/brother_lawrence_prayer.pdfIn PDF document text
    • http://muzulozak.atwebpages.com/cirrhose_du_foie_cours.pdfIn PDF document text
    • https://s3.amazonaws.com/lovetijif/harry_potter_books_1-7_special_edition_boxed.pdfIn PDF document text
    • https://s3.amazonaws.com/wiremeresegikon/que_es_el_sistema_endocrino.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_off0000e388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE388 5936 bytes
SHA-256: 04fc7bce6cc3dfa4555feab31e4911035250dddeb8bbca46daad129b119d3f36
font_01_sfnt_off0000f7b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B8 10404 bytes
SHA-256: fbebd78e9e6844b181c260b1a7912be685516c12adfaeba097bf05a4fd5a63fa