Malicious PDF — malware analysis report

Static analysis result for SHA-256 228cb03aa0df2445…

MALICIOUS

PDF

89.1 KB Created: 2021-03-12 08:08:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 70ae16cb5e857ff9c8ff751259c0a7c0 SHA-1: 3da89af9c70d4bf512cb7b83144704e9499fbc57 SHA-256: 228cb03aa0df24457bd5c43f92f64af162cb62f4a1e7bc7934f23a33a181f2bf
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The document body and numerous extracted URLs suggest a lure related to 'Udemy certificate sample pdf', likely to trick users into clicking malicious links. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the idea that this PDF is part of a link farm designed for malicious purposes, such as phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • 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 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://fokemale.ru/award?keyword=udemy+certificate+sample+pdf PDF link annotation
    • https://cdn.sqhk.co/bisegepamitu/hjf2vdS/77361287835.pdfIn PDF document text
    • https://cdn.sqhk.co/kavejufa/hhcjjjh/90_s_music_listen_online.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366360/normal_5fd2a6853df3a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380086/normal_5fe289d66dff6.pdfIn PDF document text
    • https://cdn.sqhk.co/tuponapalab/ijon3gd/billie_eilish_real_birth_name.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406771/normal_6037f1b760aa7.pdfIn PDF document text
    • http://netlysy.online/diy_folding_picnic_table_bench_plansh0x2m.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476146/normal_5fc854c33908f.pdfIn PDF document text
    • http://raifaisentgo.online/temple_escape_heroiczyifg.pdfIn PDF document text
    • https://cdn.sqhk.co/zerurukoraju/CFPzjhL/wordscapes_level_85.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385631/normal_600350f5af5ec.pdfIn PDF document text
    • http://varietystore.website/tufatipatimasic7njg.pdfIn PDF document text
    • https://cdn.sqhk.co/kisasizaro/ifjfxgj/57877029675.pdfIn PDF document text
    • http://leree4.club/609884854814599.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/bfae1047-1a71-4169-8d80-772c83f068f9/novuf.pdfIn PDF document text
    • http://wijuweluxevem.rf.gd/life_after_mod_apk_english_version.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/21152718-03b8-458e-b628-cb0970aaacd1/ejemplos_de_ejercicios_de_funciones_logicas_en_excel.pdfIn PDF document text
    • https://d89d6b52-6e76-4e18-bccb-bd7428cfddad.filesusr.com/ugd/02beb7_1e5507291de141e88c5429629b95dd1c.pdf?index=trueIn PDF document text
    • http://roxegut.rf.gd/bride_and_prejudice_movie_kickass.pdfIn PDF document text
    • http://zopusawonomiwi.rf.gd/d_d_5._0_druid_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/51277624-c71d-4b30-a768-d0ce5831b48c/que_es_un_estudio_de_factibilidad_de_un_proyecto.pdfIn PDF document text
    • http://gedawov.epizy.com/3757498074.pdfIn PDF document text
    • https://c3bb11cb-ba02-405d-8462-2b4421b436e1.filesusr.com/ugd/4c7814_3b081b2a06bb481bb4f83970d3bf2d68.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/eed2114a-3895-4e65-8ed4-e3895375e2cd/are_king_kutter_tillers_any_good.pdfIn PDF document text
    • http://dojopugoput.epizy.com/tojevomijefabagaki.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000109bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BD 5396 bytes
SHA-256: 6bd9dc4d4e740765d1b8fc1e0d17ec8f048166f2170219b69988a9ca886ba141
font_01_sfnt_off00011c0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C0A 10888 bytes
SHA-256: 7bc7ef6fb80431146717f87f046123b9db6c3d7b2935898aeefc3b18538bd526
font_02_sfnt_off00014199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14199 16164 bytes
SHA-256: c41fc46809d2260d2d1a821cef6bb00dae560fdbad380da94a93f29d012df54e