Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d631bbbf7fda155…

MALICIOUS

PDF

87.7 KB Created: 2021-04-19 19:43:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 667e50aa75cc337faa8fd579da7b1a2e SHA-1: 78cae8c8474124bc415bb950dd4bb135e30053db SHA-256: 1d631bbbf7fda155fbb07bb18d3b78db7772b3132fca4eebb73b250ae9b2c94b
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO poisoning tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to phishing or malware sites. The embedded URLs and the nature of the link farm point towards an attempt to distribute malicious content or harvest credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://fokemale.ru/strik?utm_term=what+does+color+constancy+refer+to PDF link annotation
    • https://ruzepekipup.weebly.com/uploads/1/3/1/3/131398244/1217679.pdfIn PDF document text
    • https://cdn.sqhk.co/kitujesijak/FhgUhc9/28430964297.pdfIn PDF document text
    • https://cdn.sqhk.co/sevigexew/hbj4Bha/gawokekodozip.pdfIn PDF document text
    • https://nuzepobijane.weebly.com/uploads/1/3/4/8/134885792/50910acda8.pdfIn PDF document text
    • https://cdn.sqhk.co/wofosavafiju/DwgdDND/19305157021.pdfIn PDF document text
    • https://jurutidi.weebly.com/uploads/1/3/5/3/135397820/7832678.pdfIn PDF document text
    • https://bipuvoru.weebly.com/uploads/1/3/5/3/135336843/rereja.pdfIn PDF document text
    • https://cdn.sqhk.co/kikolibub/eEgclhh/my_ice_hockey_player.pdfIn PDF document text
    • https://cdn.sqhk.co/titabofasika/f4hg2zi/39640329074.pdfIn PDF document text
    • https://cdn.sqhk.co/luveruzosu/jasjjig/surudivonapitat.pdfIn PDF document text
    • https://cdn.sqhk.co/vumorumuvogi/gsxCwnQ/clue_cells_bv.pdfIn PDF document text
    • https://cdn.sqhk.co/dasotipamu/ggii5PC/nuxuwuki.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://b81f28a7-a6cc-4df9-aebb-a76b708ee4b5.filesusr.com/ugd/df05b2_7ad0f7667c8a4b2984a05f3aa79892ef.pdf?index=trueIn PDF document text
    • https://5e446c31-fcb6-4427-a178-91ee45bbff8b.filesusr.com/ugd/4e76b8_4661675d6389487990f9b72218c95460.pdf?index=trueIn PDF document text
    • https://91313464-3f42-441e-b0e8-b27065d471ad.filesusr.com/ugd/ee9d3f_d46a80b08f2d4f9fb08f92775ddba328.pdf?index=trueIn PDF document text
    • https://6c8027e1-9878-41b3-a9ef-32ba2b6bcd02.filesusr.com/ugd/185811_b0f69c0c2dd5418194f2af45f4d2ef08.pdf?index=trueIn PDF document text
    • https://b1394492-4877-47b1-8bf2-e962974baa99.filesusr.com/ugd/3e4b7a_608909993bf342cbacfe2bd0c8d6b376.pdf?index=trueIn PDF document text
    • https://72be5e1b-4d14-4335-96ee-88463f604c48.filesusr.com/ugd/57ecfe_af1a2978ec704e37bcd17449261234be.pdf?index=trueIn PDF document text
    • https://2a983b51-2e13-4971-8c1f-a5bca3ab4353.filesusr.com/ugd/e1a791_3829b73ed89947f1bc76e1bc47306479.pdf?index=trueIn PDF document text
    • https://5c71d6b4-13b5-43a2-97a4-9a0eba4d0f4d.filesusr.com/ugd/0f1814_dee6dbca4aa945529295bfe5db767fc0.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D52 4964 bytes
SHA-256: e5d219d81e57faa79d74cf23882119afbd380a123dde4a62086878e4f833859d
font_01_sfnt_off00011e3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3A 10868 bytes
SHA-256: 7d1bdd48d2816a2a9178328e8c841a46386bf948410afd2071317e77e688bdc5
font_02_sfnt_off00014354.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14354 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378