Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c52a1b2ddc44617…

MALICIOUS

PDF

77.0 KB Created: 2021-05-25 13:24:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 515f37a7177577cf639af7b269387bb3 SHA-1: 400ac9817b23125f755f7b7c2910327f74c5645c SHA-256: 6c52a1b2ddc4461705503e6ad5618b2a19fe46d62ecc5a8230c589abf6007b20
186 Risk Score

Malware Insights

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

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 0.9997

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://crophysi.ru/strik?utm_term=algebra+2+simplifying+radical+expressions+worksheet PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4502819/normal_5ff6596653332.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427104/normal_601d6fe47905d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4401558/normal_6018ec436993d.pdfIn PDF document text
    • https://xuzubakew.weebly.com/uploads/1/3/0/9/130969304/domagagufuzed_zebuvitifedoweb_getuwowaj_duvogijav.pdfIn PDF document text
    • https://vuxijegeb.weebly.com/uploads/1/3/2/3/132302810/rokaxo.pdfIn PDF document text
    • https://femezusuf.weebly.com/uploads/1/3/1/6/131606597/e6b41a48128e0cd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454984/normal_5fe415f0c268c.pdfIn PDF document text
    • https://tuxipowu.weebly.com/uploads/1/3/4/6/134699968/bitubofexoloza.pdfIn PDF document text
    • https://xekigumi.weebly.com/uploads/1/3/0/7/130776031/bunagovozoxaz-figaza-pelozidevavikog.pdfIn PDF document text
    • https://vanufutalolu.weebly.com/uploads/1/3/1/1/131164160/tufobisalebezif.pdfIn PDF document text
    • https://furamakivagoj.weebly.com/uploads/1/3/0/8/130814247/vuwaputuzemut-riwubulajiw.pdfIn PDF document text
    • https://fozanisatede.weebly.com/uploads/1/3/4/6/134691357/4791681.pdfIn PDF document text
    • https://gilemana.weebly.com/uploads/1/3/5/3/135319463/3bc709764.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460477/normal_603e64e8cf4ab.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/4f2b61d4-9cc5-4b5b-98c2-3fa16b70baaf/python_check_if_dictionary_contains_keys.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f25ea48f-efa8-48a4-92af-6270e9d4f32d/microsoft_excel_assignments_for_beginners.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d577a5f0-5906-4d17-a309-a6a1df45d402/40597405012.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d069f255-3e93-49fe-8faa-995dee10392c/how_to_prepare_for_google_engineering_manager_interview.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4eba3e77-dc76-4854-8590-059c52092756/how_do_i_find_the_4_digit_code_for_my_tv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2132fed0-402f-4370-8690-838ddd14adb2/formato_de_carta_gantt_en_word.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3d7120d2-c0f6-40b8-9728-4e2f9e4212fa/harry_potter_book_set_pottermore.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_off0000ed4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED4A 6156 bytes
SHA-256: 4a6d3f58895aa68ab2f8f0218af57dee4225eed71c711a29a4993fec593d532e
font_01_sfnt_off00010234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10234 11196 bytes
SHA-256: 5b7147dff278e1b7f25e7a036643b3f6a62a75d9fab64a01138ee4e82be48230