Malicious PDF — malware analysis report

Static analysis result for SHA-256 8df563afd09b6be2…

MALICIOUS

PDF

80.3 KB Created: 2021-03-08 21:04:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 9c743098ab94884296a4f72b4c08120f SHA-1: 737828d0ad725479c77617ca1a89baf01d606107 SHA-256: 8df563afd09b6be27a2fc51fffac853d657cadebbdc51047dde797701f18f059
126 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 hosting services, suggesting a link farm designed to direct users to potentially malicious content. The ML classifier strongly indicates maliciousness, and the presence of embedded URLs further supports the attack pattern of luring users to external sites. No scripts were extracted, but the overall structure and URL distribution are indicative of a phishing or content-luring scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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://resalured.ru/123?utm_term=the+great+courses+algebra+2+workbook+pdf PDF link annotation
    • https://rotonozi.weebly.com/uploads/1/3/5/3/135315410/2041663.pdfIn PDF document text
    • https://cdn.sqhk.co/zesonixiv/cjgxwCp/76417232239.pdfIn PDF document text
    • https://rapusixub.weebly.com/uploads/1/3/4/6/134631860/xepilasuloxeg.pdfIn PDF document text
    • https://cdn.sqhk.co/felegabiw/evjfyJT/download_snake_io_mod_apk_android_1.pdfIn PDF document text
    • https://cdn.sqhk.co/lojadisexudo/jiTge7N/puffin_tv_browser_free.pdfIn PDF document text
    • https://nusutaligufobam.weebly.com/uploads/1/3/5/3/135393176/xovikikejivowel_riludamajipunok_tajigufif.pdfIn PDF document text
    • https://cdn.sqhk.co/futevanu/ifDRyhe/wradio_en_vivo_loret.pdfIn PDF document text
    • https://cdn.sqhk.co/fowijuseziju/mib9Kge/70505593963.pdfIn PDF document text
    • https://pusurezifokuni.weebly.com/uploads/1/3/4/3/134317864/jinesuwugosoji-tekedakalud-pofikowusejunep-wabisa.pdfIn PDF document text
    • https://xunasumip.weebly.com/uploads/1/3/2/6/132696393/wefoxoko-jovuradufaf-todixisovexu.pdfIn PDF document text
    • https://cdn.sqhk.co/xafeperale/jeAgkgh/home_depot_flooring_installation_calculator.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/4ef9a603-6ad7-41c3-b53b-73e6a950739d/what_is_definition_of_curriculum.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8669b27e-7787-4329-bb5e-7f9082383d0b/43901275151.pdfIn PDF document text
    • https://451b78f8-089e-4d4d-bc4b-60abb621f7e6.filesusr.com/ugd/7ef0dc_dc98f685d1424229a5bbcbc30d9a438c.pdf?index=trueIn PDF document text
    • https://d75bbb92-b0e4-4b50-83e6-2443e695523b.filesusr.com/ugd/bc73b9_c94bfab22b6b4bfca34fcb66fb0dd500.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd2b9e91-6b0d-4685-85e6-23a9c33d1770/rexadolibogenexaxe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/37a91d3d-1395-4180-87c3-dcad26bcbf43/the_count_of_monte_cristo_chapter_35_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/76c7801f-b0a2-4231-810d-09b285402252/30794059072.pdfIn PDF document text
    • https://67dec473-0a9c-497c-80b1-62a4c84c5046.filesusr.com/ugd/0aab01_4ff9c35b4d9c4ecc89b4bb02032de960.pdf?index=trueIn PDF document text
    • https://3e3188f7-d9e9-48da-9af6-4e6760718ee0.filesusr.com/ugd/4f7562_615ba10e9bed40ac96b082f39cbc2bfb.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f4085fe-de00-4ec2-ad6f-58320b27d6e6/how_to_resolve_forces_into_x_and_y_components.pdfIn PDF document text
    • https://3bdad275-8828-414d-9063-9532e035d791.filesusr.com/ugd/c67d0c_bea7645b830d4c769624057ac0fd9d78.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_off0000fa7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA7C 5796 bytes
SHA-256: a87fa7d95ebbaa07fa6daf70a958e7b7f37f45e7bf8a08011c9ca90e78ac2a72
font_01_sfnt_off00010e43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E43 11132 bytes
SHA-256: 93f2a8cf19ea65e75dd129f75701299b48254eeb63ef78e3732cce3311c3926e