Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ca8423def912841…

MALICIOUS

PDF

77.4 KB Created: 2021-03-24 16:39:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 6fcf7266aeb64793e80d59bf133fb299 SHA-1: b861eb8ed10dd24190ae2bb4dd82d1c6cdb9d4a8 SHA-256: 8ca8423def912841d2f03b9ab7b4ca8ded628993a6890ba80b9d35ab779bb9b6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF that contains a large number of external links, many hosted on disposable domains, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The primary attack pattern involves luring users to click on these links, which could lead to credential theft or malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://seumenha.ru/wix?keyword=d%2526d+arcane+archer+revised PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4479674/normal_5fe63737a0ddc.pdfIn PDF document text
    • http://zuviwadakaji.22web.org/9779260844.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446155/normal_601fa91812fa7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387424/normal_6015fc6a64fed.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
    • http://kitosigefowo.epizy.com/88052471113.pdfIn PDF document text
    • https://abee6ad4-cf47-459a-954e-22b9b9bb30ad.filesusr.com/ugd/4bdc6d_732be485795e45edbab22ff5c2c47db3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ffb52b4-8cb4-4c73-965f-9a657b61bd20/newton_1_law_of_motion_formula.pdfIn PDF document text
    • http://bigagapafobari.rf.gd/irregular_action_verbs_worksheet_2nd_grade.pdfIn PDF document text
    • http://jefelaxe.epizy.com/64464351574.pdfIn PDF document text
    • http://tefesapebeto.rf.gd/tofuvufobukuxogusawubor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2201a837-0e7d-4c98-9e9b-c9e87a873dba/53056123815.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3d4647b1-a3c5-40d2-9005-4fb850518655/a_dolls_house_henrik_ibsen_full_movie.pdfIn PDF document text
    • https://e8dc5420-792a-4861-90db-09cfc8d8a7d1.filesusr.com/ugd/1378f5_7b6d3bb7140c4ab2b9155d9f865e807d.pdf?index=trueIn PDF document text
    • https://5b0e1d79-1acc-45ba-a965-31015372eee8.filesusr.com/ugd/67f5f7_8c4115bb43fb44809e6c561427007b0c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/dc99f5f0-d112-4b24-9c71-1ec8df26286f/shark_cordless_pet_perfect_vacuum.pdfIn PDF document text
    • https://c7f0abc7-d23b-482d-bd16-0771495bb668.filesusr.com/ugd/bb13a2_995baa00a49a4054ae44c29a14897826.pdf?index=trueIn PDF document text
    • http://reduxaxu.epizy.com/4661997649.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b291f766-54cf-43c4-b5cd-c9e69a062314/how_to_fix_remote_control_buttons_not_working.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eaf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF4 3484 bytes
SHA-256: 866fd8f85cd0130a59e26d5d2ef72782554194052287c2ce3d346dbb443db71f
font_01_sfnt_off0000f661.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF661 10692 bytes
SHA-256: 6b441251191fa465b9a9b673b1829201ebad4fbe02f120cb217b19efb4609d74
font_02_sfnt_off00011b0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B0A 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e