Malicious PDF — malware analysis report

Static analysis result for SHA-256 e731cf39a4e426c8…

MALICIOUS

PDF

74.6 KB Created: 2021-04-08 19:33:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: bd65c47c638a9b00ee89141911bab430 SHA-1: deb052ecfb2e092b57c84739895dac17b00d4ced SHA-256: e731cf39a4e426c8adaa909167543728fbdefc70a572011b8d92aa5fce1258d6
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 0.9996

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 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://xajibur.ru/strik?utm_term=star+wars+thrawn+audiobook+free PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4474456/normal_60651c55387b5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408001/normal_6012a382746b3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491934/normal_6017260bb20cf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366402/normal_602204a0313f7.pdfIn PDF document text
    • http://dololebajug.scienceontheweb.net/decimal_place_value_chart_5th_grade.pdfIn PDF document text
    • http://kindraretterath.com/absceso_hepatico_manejo_quirurgicovq9ww.pdfIn PDF document text
    • http://nesobaka9.xyz/addressing_barriers_to_learning_a_south_african_perspectivevg6ke.pdfIn PDF document text
    • http://chempion.coffee/88527195737jgjmg.pdfIn PDF document text
    • http://cabinetshq.xyz/famibozusupadi4m.pdfIn PDF document text
    • http://xawamiwupajev.mygamesonline.org/wugola.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/4045c03a-0c41-4a03-a16f-b287e875af85/luxawofob.pdfIn PDF document text
    • https://46fb9a51-9e16-4ad8-811e-2f7ed01702f7.filesusr.com/ugd/53363c_7549f0358da442efbe112adcd704f838.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/6fc4e0c3-d2fa-42e3-bf0c-36246976b576/rutijojeroze.pdfIn PDF document text
    • https://be8414c4-f2d5-40c6-b8a8-1a5561a1dac7.filesusr.com/ugd/a452ea_99464cee2fac407fbc9a99c73109f919.pdf?index=trueIn PDF document text
    • http://tujupifirafadus.myartsonline.com/42017246148.pdfIn PDF document text
    • https://b913155d-2712-4fd4-bcc6-651970a8c456.filesusr.com/ugd/e39924_fc3a73b0905d4c658cda9aa192a5e111.pdf?index=trueIn PDF document text
    • http://tonavisuma.onlinewebshop.net/94696734965.pdfIn PDF document text
    • https://f61a8d15-835b-4c36-a3db-e4ead73ab13f.filesusr.com/ugd/e9f5f3_4600452c49c0487ba41a3d262df02a32.pdf?index=trueIn PDF document text
    • https://cf075d60-af7c-4c71-a16c-5c8c125a9bb7.filesusr.com/ugd/cc03df_88df5d83626f42a68653bb1844077fa2.pdf?index=trueIn PDF document text
    • https://1e16f6d7-285b-4488-bf07-d3e24ac90e20.filesusr.com/ugd/417718_198c48bde93f4446bb20a2485a2dd020.pdf?index=trueIn PDF document text
    • http://gixarewujedel.atwebpages.com/what_to_do_if_monitor_wont_turn_on.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_off0000e46f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46F 5360 bytes
SHA-256: fa999f0517321382ba51e50848f95ffff4226d693aac6164ae5bb5567a17c6c7
font_01_sfnt_off0000f6b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B6 11536 bytes
SHA-256: 1f96bec95c1d63dde146e8c65cac5206dc12bbb0994856760d4f953b133f740c