Malicious PDF — malware analysis report

Static analysis result for SHA-256 a520cf0669815d78…

MALICIOUS

PDF

87.3 KB Created: 2021-03-21 07:27:11 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 050e36f4d099fa59fba4263cc84b0ede SHA-1: 40c501e3a8b63e0391226dca2399200a8a50a753 SHA-256: a520cf0669815d78fa2e73f48d781f8934fb4eb829aefbfbd316c14ef30032fa
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jottigo.ru/123?utm_term=geeky+medics+cardiovascular+exam+pdf PDF link annotation
    • http://xevanaz.iblogger.org/61187371464.pdfIn PDF document text
    • http://zexaribamemavi.sportsontheweb.net/gebidomejemowewipijab.pdfIn PDF document text
    • https://cdn.sqhk.co/jolodovi/hjiejcS/flight_simulator_2018_hack_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/foxoxaze/igiEhed/modern_sofa_set_designs_for_drawing_room.pdfIn PDF document text
    • https://cdn.sqhk.co/zapimafe/jakjiSf/boninoranutaxuxaziz.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/74dd3270-a7f8-45d0-80b6-fcb5daba0932/rutakamiwazimasufevu.pdfIn PDF document text
    • https://3dd85f33-233b-4b3c-8e53-142bc8307eec.filesusr.com/ugd/8df890_45f185cb9e064c3dadc640c7465f4a73.pdf?index=trueIn PDF document text
    • https://1cf095b7-1d29-4152-b82c-7733cf7ba0c7.filesusr.com/ugd/c1de29_b4bca329f20b4ba98606cfef2a65f8c9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c2fb6ffe-e52f-4397-92a1-4ad7150a8276/top_bar_bee_hive_designs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ff2163f-96fc-498c-a3ff-9686067de4f0/kunejunefuropola.pdfIn PDF document text
    • http://susabumo.atwebpages.com/79993967330.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/418131eb-ff46-4dd3-9669-4ae05bdb2b1b/lexus_rx_350_price_2010_in_cambodia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5ec59dda-b54a-4108-92d7-5ef45992904f/22335122482.pdfIn PDF document text
    • https://69cf8a46-0d3d-4b71-8fd1-93df925da18e.filesusr.com/ugd/e4064d_e5bbc1e93de24c79adb38373b7e03ec6.pdf?index=trueIn PDF document text
    • http://rukukuwozar.epizy.com/bebazivanikekisutuxipugaw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66aa4c60-4691-48c3-8f02-9e6ba5abb111/how_much_does_geek_squad_cost_to_fix_a_computer_screen.pdfIn PDF document text
    • https://21e323bd-7fdd-46e9-a6c7-4880e76d7610.filesusr.com/ugd/0a51c1_71bf7f4aaf094e64bc3783bf4673b319.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7acf504e-e621-45b4-a4f5-4bcce1c209cb/rozunifijuli.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_off00011772.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11772 5624 bytes
SHA-256: 457ce8379d79cb06d07bddde267160bf3515371f760cb489ba16e426f358a5c5
font_01_sfnt_off00012a9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A9C 10604 bytes
SHA-256: 5405eb933905058051984eecb07cd784802acf44791c75cd34d29e5dcde0f273