Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b285c8e8515d872…

MALICIOUS

PDF

72.8 KB Created: 2021-04-29 12:10:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: ad199015985cd1fb7b67d4e5fd9509d0 SHA-1: 9462c53b5b544348be71217c720b8bd8214d94e0 SHA-256: 8b285c8e8515d872e2950d420e6b166f1dece4ed3e403407b772010a29dbfe62
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many of which are on disposable hosting, suggesting a link farm designed to redirect users to potentially harmful content. The primary suspicious URL identified is https://nipisod.ru/strik?utm_term=libro+de+fisica+1+bachillerato+tercer+semestre+contestado, which is likely part of a phishing or malware distribution scheme.

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://nipisod.ru/strik?utm_term=libro+de+fisica+1+bachillerato+tercer+semestre+contestado PDF link annotation
    • https://cdn.sqhk.co/dabebasavus/yidGYjh/transfer_news_twitter.pdfIn PDF document text
    • https://cdn.sqhk.co/foseziwate/zf1hdia/bloons_td_5_monkey_lane_impoppable_guide.pdfIn PDF document text
    • https://cdn.sqhk.co/tebolugex/jifhaGQ/leather_motorcycle_pants_near_me.pdfIn PDF document text
    • https://cdn.sqhk.co/zatejurix/jepmcjj/erza_scarlet_fairy_tail_transformation_live_wallpaper.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415519/normal_600e103925e9d.pdfIn PDF document text
    • https://nujirami.weebly.com/uploads/1/3/1/3/131384028/e9f547c44c8.pdfIn PDF document text
    • https://cdn.sqhk.co/jisepozidis/4EhjoaU/geophysics_journal_latex_template.pdfIn PDF document text
    • https://cdn.sqhk.co/lomotutuwe/hcinpqh/57352226248.pdfIn PDF document text
    • https://cdn.sqhk.co/refuvowur/ghELlep/booster_tiktok_technical.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421767/normal_601de199dd854.pdfIn PDF document text
    • https://bilugejedegigel.weebly.com/uploads/1/3/4/0/134017605/tomotuso.pdfIn PDF document text
    • https://vixodago.weebly.com/uploads/1/3/4/7/134716619/zosezivuvul.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cf587a47-7c2f-4f55-8bbb-21a4c73503f7.filesusr.com/ugd/8ea597_de5051697af64a558df9f591d21bda85.pdf?index=trueIn PDF document text
    • https://12c48f50-3553-44c7-a31c-19fc5df83d07.filesusr.com/ugd/7e0eb0_efb167cc787d44748b7e851989a1e630.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/97521d0d-838e-40f0-a208-7253f0c01fee/genie_gict390_how_to_replace_battery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a2a573ff-9f35-43f8-95f8-7c44ba82f5b5/brother_hl-2170w_wireless_setup_mac.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fe01d313-1ae5-41cd-9324-829f86d91856/guwazolumipegejitubikavem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f41a3a6-422e-4c4e-b21b-87b2fb9c9639/resumen_del_libro_el_caballero_de_la_armadura_oxidada_corto.pdfIn PDF document text
    • https://4ceac43d-3374-4736-8926-b47930641487.filesusr.com/ugd/3b1191_53ee43441b7a47b08fdf7d3e6e36d0a4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/28c43893-8341-4259-9092-59ac65d0eb2c/towufopinareb.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_off0000e00c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE00C 5392 bytes
SHA-256: 96567ed7efbd5af6c209fab001485b192a958635e422f751e26a3f99fb7abdb1
font_01_sfnt_off0000f245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF245 10864 bytes
SHA-256: 7da8dac8f3b2492e7ce94526e2e7a4479db15ca8fbcaf1d38872790cb62ab322