Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f0c273ef3e68c49…

MALICIOUS

PDF

79.2 KB Created: 2021-04-04 20:19:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: cf44efd2b01f7cb7c65be1e4885ebd93 SHA-1: 69ec4c549cdb10a39ace98e2723e1bf4ba280b39 SHA-256: 1f0c273ef3e68c491021421a3a7f09d45d6d1c4d87aa219bb17f5cd6667b92e7
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to domains associated with link farms and disposable hosting, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. ClamAV and an ML classifier also flagged this PDF as malicious, specifically as a phishing trojan. The primary URL, https://mezovuduw.ru/award?keyword=cds+2+exam+syllabus+2020+pdf, suggests a lure related to exam syllabi, likely to disguise the malicious intent of redirecting users to other potentially harmful content.

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://mezovuduw.ru/award?keyword=cds+2+exam+syllabus+2020+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4392667/normal_6051c4a9e5f80.pdfIn PDF document text
    • http://baltika-trans.ru/79217856581jr8t7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391599/normal_6018606b8acf6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4470687/normal_60015e0493e47.pdfIn PDF document text
    • http://avtovishki-msk.ru/tejazagil487g.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481839/normal_606369de0e661.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453098/normal_601e50d34306a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://a72b158e-cead-41d6-a0b3-8518216316a4.filesusr.com/ugd/35c6e2_83fd6085e700427392a3fae166b8cf1a.pdf?index=trueIn PDF document text
    • https://6ddb26ad-aa8e-4a3e-a925-5cef6fc035e1.filesusr.com/ugd/d3d820_4b9c9cdb942c461eb24e00e9bfd2f68d.pdf?index=trueIn PDF document text
    • https://43e59f28-96d7-4988-bcd6-55bc25f76e69.filesusr.com/ugd/372bdc_dae867f3037347edb24e2b04a160b17e.pdf?index=trueIn PDF document text
    • http://nesowoxaxisaxa.rf.gd/24257025400.pdfIn PDF document text
    • http://zarevasagi.epizy.com/71983087111.pdfIn PDF document text
    • http://deroselewem.epizy.com/how_to_set_my_adidas_digital_watch.pdfIn PDF document text
    • https://36c7e617-1221-4173-b726-d5bce2878801.filesusr.com/ugd/610d21_009d39c5716642619e08195d4413bd5b.pdf?index=trueIn PDF document text
    • https://c6111751-42b6-464f-a8b1-832d492ff999.filesusr.com/ugd/3d0627_972bdbe39cf544fba166c665b68013c6.pdf?index=trueIn PDF document text
    • https://676a7a22-5bec-432e-92e0-9d4a0a27851c.filesusr.com/ugd/a1fb72_016d63db921d40a887a75dd392825923.pdf?index=trueIn PDF document text
    • https://45f61934-b4a1-4335-a9e3-e142d9465b5b.filesusr.com/ugd/0dd040_a61179401ca6490799699c7073e3b7ac.pdf?index=trueIn PDF document text
    • http://tasubad.rf.gd/raw_functional_training.pdfIn PDF document text
    • https://8f0c9b82-9570-4081-bbb7-5e23a534ea09.filesusr.com/ugd/7008f3_67d95b074a7f40de9b89cee04ae24e38.pdf?index=trueIn PDF document text
    • http://fezumijuva.epizy.com/washing_machine_troubleshooting_guide.pdfIn PDF document text
    • https://ef5e9b3f-1a8e-4c79-9b60-34b8f8133c96.filesusr.com/ugd/18574e_87acefe232134bda8613fd8b4ce52854.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C6 5580 bytes
SHA-256: 3e9886183649b692e706b54f2789cd0e78fe45898574362a961e6efcd5a750f9
font_01_sfnt_off000108b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B2 11416 bytes
SHA-256: ac1cf9a8283156f3d24093b44de7cb213ddf079507dd3d2f3d22d5c1d3b4de01