Malicious PDF — malware analysis report

Static analysis result for SHA-256 21ec304209176a43…

MALICIOUS

PDF

74.7 KB Created: 2021-05-10 06:40:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 31ae17f3f3cacf1f3f4579cc07b04b64 SHA-1: 711dc13564523e4d7c825313faa5abf5675b0b4f SHA-256: 21ec304209176a434556a6bef548d2501c13bc249660d0bca86d6b60fece608c
134 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many pointing to disposable hosting and employing UTM parameters, indicative of a link farm or phishing campaign. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, appears to be a lure related to 'sailboat racing rules' to encourage clicks on external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://gimoguvi.ru/strik?utm_term=sailboat+racing+rules+explained PDF link annotation
    • http://guromufupadaf.iblogger.org/asset_management_corporation_of_nigeria_act.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383470/normal_601111c6ac53d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458827/normal_6061fd26eb99e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412584/normal_603835da400af.pdfIn PDF document text
    • http://kovatafob.mypressonline.com/quadrafire_pellet_stove_insert_parts.pdfIn PDF document text
    • http://iqecoportal.ru/nokunoviwepixenuj3ixh9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368759/normal_600edac1f28e5.pdfIn PDF document text
    • http://pro-komp-master.website/vujowabaxhdzi5.pdfIn PDF document text
    • http://levantegroup.net/ryobi_3100_pressure_washer_troubleshootingxs9wa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vebagakid.onlinewebshop.net/marketing_research_an_applied_orientation_free_download.pdfIn PDF document text
    • https://95a57b4d-a24c-4412-bd87-88f4f885d252.filesusr.com/ugd/011e4b_ae1ea00dcfe34cfd91dfde22d76fc67d.pdf?index=trueIn PDF document text
    • https://49f3a523-2ddb-4f17-a073-729d67a362fa.filesusr.com/ugd/18c683_87b3462f69df437085072a9fab0e6211.pdf?index=trueIn PDF document text
    • https://c6926203-1eb9-401e-9afa-11f61f201807.filesusr.com/ugd/685707_b9c0378a64ba4191856238d147bf0035.pdf?index=trueIn PDF document text
    • http://vusatalejud.epizy.com/lugepuwenejanujuwa.pdfIn PDF document text
    • http://fezigaf.epizy.com/kujigidegokugiwon.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4de5a0af-f13f-43a7-ab5b-bc70338bf135/zen_in_the_art_of_writing.pdfIn PDF document text
    • http://nozulorot.epizy.com/62325932042.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/041a4e16-954a-4ec8-b113-a23a3b2b08e5/how_to_reset_samsung_dryer_heating_element.pdfIn PDF document text
    • http://tajiroxajesolut.atwebpages.com/39676221024.pdfIn PDF document text
    • https://51f47fa2-20f7-4ec4-bb91-8ae4aee689b4.filesusr.com/ugd/917232_073c2c3f5b174ccc905569c7eeb6b39f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3e1db4fc-9f7e-455c-966b-78691075dc86/how_to_clean_a_vicks_germ_free_humidifier_filter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35d660ed-f909-4061-bf08-55d6c842cd94/pusakuwij.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_off0000e4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4E1 5552 bytes
SHA-256: e3187a28987ce22c26ad84ddc3f529a1ff1e0055237972e696d2c466f4aa5284
font_01_sfnt_off0000f7cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7CC 11152 bytes
SHA-256: ddb3397814e7193f3757a3a5b64bf0e9c0a3326602a18912aa8828b9a9f88e49