Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf00b51d2ce2d646…

MALICIOUS

PDF

76.7 KB Created: 2021-04-03 18:40:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: de64baa6f2708e44054311bc1efa035d SHA-1: 11c8cab947d65558c2f5b4894aee532d89cde58e SHA-256: cf00b51d2ce2d6465af6f5e82129e7f0b6b362d70ed5f864968b109117e182a3
186 Risk Score

Malware Insights

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

This PDF document contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO manipulation. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jacksth.ru/strik?utm_term=is+starbucks+coconut+milk+good+for+you PDF link annotation
    • https://cdn.sqhk.co/jijipidub/eUhbMgi/69696083681.pdfIn PDF document text
    • http://bamulojamojexut.22web.org/balancing_chemical_equations_pogil.pdfIn PDF document text
    • https://cdn.sqhk.co/putuziboki/geZyggi/4748372563.pdfIn PDF document text
    • https://cdn.sqhk.co/xadakede/Xjaegm1/cool_lego_wallpapers_hd_free.pdfIn PDF document text
    • https://cdn.sqhk.co/wuzosiboweja/0jdjkaj/free_download_open_world_car_games.pdfIn PDF document text
    • https://cdn.sqhk.co/gorokipo/iheYjaq/infographic_resume_template_docx_free.pdfIn PDF document text
    • https://cdn.sqhk.co/kawonidoza/XCFYmjc/katotijoratanozofafedu.pdfIn PDF document text
    • https://cdn.sqhk.co/dasadogiso/ifAvijD/wikuzofapomokimixapikofu.pdfIn PDF document text
    • https://cdn.sqhk.co/webepinovet/YjcfCqY/skydiving_costume_ideas.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://malunazix.rf.gd/tigipaxixumotisade.pdfIn PDF document text
    • https://68f2566a-c586-4d15-a5d1-3a72044c38f3.filesusr.com/ugd/ecec20_2139ded6ed8c468e951cd2772df97211.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f23f6b6-e042-4aa2-b8b4-b15514f29f37/group_theory_chemistry_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c5b45077-c824-4a5d-b624-dae466dee719/83453467339.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/124cb0b4-4187-4c7b-b1ca-a4d327dc11d3/python_set_add_all_from_another_set.pdfIn PDF document text
    • https://7737876a-f762-42ef-af6f-18b78abacabf.filesusr.com/ugd/9066bd_a2030270db3747f4b9fcf8b003c54c2c.pdf?index=trueIn PDF document text
    • https://57ead060-d7b3-4f59-a803-6c9b47c0028a.filesusr.com/ugd/f30481_3ae7f15a817345f38883b6d2676b0a6f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ce1a3c8-ac58-41ed-8f77-e2b2539a445a/evh_5150iii_50w_el34_1x12_combo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3c881aa-9bf4-47bf-9317-306d49d050ad/que_es_la_foto_tumblr.pdfIn PDF document text
    • https://a529afa0-707c-494d-9cee-e9df2360aa12.filesusr.com/ugd/a6e48a_c7d5b985b5ae4c7d910e18922c693128.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_off0000eba0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA0 5584 bytes
SHA-256: 705a23590dddc63ed79200444293d3c2d149ac42af6b39407532ab3770dff93f
font_01_sfnt_off0000fe9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9B 10976 bytes
SHA-256: c6175e6103ddfe983cfb7cfde513a6bc7c10e194578362d5252dca5ce76a82bb