Malicious PDF — malware analysis report

Static analysis result for SHA-256 be6a4bcd321658ea…

MALICIOUS

PDF

82.9 KB Created: 2021-04-03 10:08:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 3bbcf49ba23d65dafecbe99fff81d239 SHA-1: 592f6678ddceb1a6b8fcd4ab448d21334adb5e87 SHA-256: be6a4bcd321658ea3104a1774b9b7abc522d4e3b2602ff681669ad06a53e3c80
186 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded external links, a technique often used for SEO manipulation or phishing. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically flagging it as a phishing trojan. The document body, though heavily obfuscated, contains references to 'fuel injection' and the authoring application 'wkhtmltopdf', suggesting a lure to disguise the malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://druttle.ru/strik?utm_term=what+are+the+benefits+of+fuel+injection PDF link annotation
    • https://cdn.sqhk.co/fetebutujo/hj8idgh/informatica_data_quality_interview_questions_and_answers.pdfIn PDF document text
    • http://uchebnoe.website/nugenevufibupudimezi4mqkz.pdfIn PDF document text
    • https://cdn.sqhk.co/ninuxoti/hhcjghd/candy_cake_maker_apk.pdfIn PDF document text
    • https://cdn.sqhk.co/vavewiminiv/6jhghjj/break_it_to_me_gently_angela_bofill.pdfIn PDF document text
    • https://cdn.sqhk.co/supesuvepo/ij3pCjf/hangout_holidays_rishikesh.pdfIn PDF document text
    • https://cdn.sqhk.co/lafuwexale/gQa0iae/wehrmacht_uniform_for_sale.pdfIn PDF document text
    • https://cdn.sqhk.co/suxujaba/icV7fjg/summer_bucket_list_ideas_for_college_students.pdfIn PDF document text
    • https://cdn.sqhk.co/miwataxanis/Phphahh/87627769346.pdfIn PDF document text
    • https://cdn.sqhk.co/nosimasiv/jgcifXX/laxonenazukajulipa.pdfIn PDF document text
    • http://xejopegig.mypressonline.com/absolutist_state.pdfIn PDF document text
    • https://cdn.sqhk.co/gufezima/ieecgg3/cheat_droid_pro_root_free.pdfIn PDF document text
    • http://chestlune.online/sanadizojusomoxokakala1t9zz.pdfIn PDF document text
    • http://bazunujovi.scienceontheweb.net/how_government_encourage_entrepreneurship.pdfIn PDF document text
    • http://blancer.xyz/kexuvazoxoduwisk9sn4.pdfIn PDF document text
    • http://lazotub.mywebcommunity.org/95938802724.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6376acfe-5884-4251-b3d5-19a03c044549.filesusr.com/ugd/de3d83_76d3a85dee9e4d528a1f35463cfef0a8.pdf?index=trueIn PDF document text
    • https://4b4b92a8-4ac5-4030-97d5-af0917f8c077.filesusr.com/ugd/0251f0_48cbeae60f054b60aaa4ff6771e0314a.pdf?index=trueIn PDF document text
    • https://eb7ae0bc-69c2-4833-8adb-ed465737bb77.filesusr.com/ugd/23493e_57d731c40b324840ac06caa1f52ef140.pdf?index=trueIn PDF document text
    • https://be08d7d4-326a-4801-be9d-4496af17a43b.filesusr.com/ugd/d31907_ab0557172d074004bd58dea97ad8adb6.pdf?index=trueIn PDF document text
    • https://5cbbff6b-7c47-4fbb-abda-9de5069fbc88.filesusr.com/ugd/1a89c8_fee26d7ddfc1407dba08aa1dae8199f9.pdf?index=trueIn PDF document text
    • http://bifiwapaz.onlinewebshop.net/60970968045.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_off00010585.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10585 5196 bytes
SHA-256: 7441bd89b21497013b87603e878752840b2bebc9a13dc4890ee021bcb2ee8737
font_01_sfnt_off00011740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11740 11312 bytes
SHA-256: a94ae3aff998bf9dd7afabe645035933863882682b07dca0e9bc704ae4fa2d7d