Malicious PDF — malware analysis report

Static analysis result for SHA-256 c86fce0bdcb0fc38…

MALICIOUS

PDF

72.5 KB Created: 2021-02-05 16:39:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-03
MD5: 540edd1be4de047c1f42294f2380c812 SHA-1: 591bce5090ee435f86ec0f7a1335e003a21ca8a2 SHA-256: c86fce0bdcb0fc38d8c99837d4884d125bf34c940869dfa75da45778ddadf1cf
224 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. It contains multiple links, including one pointing to known malicious redirector infrastructure at 'https://yafferge.ru/123?utm_term=udemy+coupon+code+jan+2020'. The document body, though heavily obfuscated, appears to reference 'Udemy coupon code jan 2020', suggesting a phishing lure. The presence of numerous links on disposable hosting further supports a malicious intent, likely to distribute further malware or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/123?utm_term=udemy+coupon+code+jan+2020 In PDF document text
    • https://static.s123-cdn-static.com/uploads/4476429/normal_60076f908ed3e.pdfIn PDF document text
    • http://tehnopolis.org/xonefibuvixadijiganuwaguldzumq.pdfIn PDF document text
    • https://ziwuwozapa.weebly.com/uploads/1/3/4/5/134517717/dobado-bomulog.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491151/normal_6016b5a0afa77.pdfIn PDF document text
    • http://hotsales-com.xyz/above_all_powers_lyrics_pptzdxw5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427105/normal_5fccdb91201e8.pdfIn PDF document text
    • http://kogovokuriboti.22web.org/79834803481.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387701/normal_5fea246b93ced.pdfIn PDF document text
    • http://kayikciakademi.com/56941454611yn29z.pdfIn PDF document text
    • https://xutativapejan.weebly.com/uploads/1/3/4/5/134521393/warurotegodegitog.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503390/normal_600d1d56cec90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403543/normal_601615451d07e.pdfIn PDF document text
    • http://all-system7.xyz/infiniti_g35_manualh984l.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417998/normal_5ff3c6dec7ec0.pdfIn PDF document text
    • http://dvigatel.guru/realismo_juridico_genovesfekoh.pdfIn PDF document text
    • http://axecheat5.xyz/detailed_lesson_plan_in_math_free_download6f7jf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475376/normal_601cf02f4a63a.pdfIn PDF document text
    • https://molawaxurot.weebly.com/uploads/1/3/4/6/134699933/8168757.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://juxugalipexobow.epizy.com/chew_wga_0._9_windows_7_ultimate.pdfIn PDF document text
    • http://zedotedifajo.epizy.com/ain_t_it_funny_song.pdfIn PDF document text
    • http://fupuzujovo.epizy.com/rewrite_the_sentences_in_passive_voice.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_off0000da68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA68 5356 bytes
SHA-256: b6e2c55dfc0c42c51770894d83df1e8cbee3e44c581dbabaff53bab6337b24c6
font_01_sfnt_off0000eca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA2 11780 bytes
SHA-256: 7170d07ff7e24bc04e0e086718d2d4f2bd4a1cb410982ebe91b1114908439174