Malicious PDF — malware analysis report

Static analysis result for SHA-256 8735f3e3da591bcd…

MALICIOUS

PDF

95.3 KB Created: 2021-04-07 09:29:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: bc0ddc40f137b569f14007289ce94f81 SHA-1: ac9ece518656c2e6dc06e888ef884d1c2fe12cc6 SHA-256: 8735f3e3da591bcd9c217ac26a6a5917b6a3b08051bc9d2d42f948ac11a14391
184 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or known redirector infrastructure. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK specifically flags a URL pointing to a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery, disguised as an answer key.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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
  • 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.
  • 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://crophysi.ru/wix?keyword=pltw+answer+key+5.4 In PDF document text
    • http://lejunuzegakikuv.mypressonline.com/gibokirusirenodekupel.pdfIn PDF document text
    • https://kuvinobugo.weebly.com/uploads/1/3/1/3/131383931/3686295.pdfIn PDF document text
    • https://femezusuf.weebly.com/uploads/1/3/1/6/131606597/99e83bd96aa320.pdfIn PDF document text
    • https://cdn.sqhk.co/mamidusidozu/yXjjSig/panutexur.pdfIn PDF document text
    • https://cdn.sqhk.co/tuxonewebuke/boeXiiO/vilizasakogavibozo.pdfIn PDF document text
    • http://fumatiw.mypressonline.com/comunicazione_assertiva.pdfIn PDF document text
    • https://cdn.sqhk.co/piwuzuberaze/Qigjiih/werinufi.pdfIn PDF document text
    • https://vedefagam.weebly.com/uploads/1/3/0/8/130814874/goxuvifokun.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464523/normal_602e52e47a888.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417405/normal_602d412a8a0fd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386347/normal_6044e7b09fd94.pdfIn PDF document text
    • https://resusogid.weebly.com/uploads/1/3/5/3/135346187/kelofujoforuneler.pdfIn PDF document text
    • http://nigemutekilum.mypressonline.com/after_anna_todd_italiano.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4390642/normal_5fe58013d4f16.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4372086/normal_5feb4f992c85b.pdfIn PDF document text
    • http://wotidoteked.mywebcommunity.org/78911560181.pdfIn PDF document text
    • https://cdn.sqhk.co/vasinabew/wjjKpIl/princess_cat_nom_nom_evolution.pdfIn PDF document text
    • http://vuvulusigi.scienceontheweb.net/jabexegaxagumezus.pdfIn PDF document text
    • https://buzapakamewogu.weebly.com/uploads/1/3/4/3/134366326/kefum_dilixijawu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/xisefowu/how_to_design_a_functional_training_program.pdfIn PDF document text
    • http://kibozitasosisan.epizy.com/gate_2020_instrumentation_books_free_download.pdfIn PDF document text
    • http://kodibonu.rf.gd/algebra_1_regents_study_guide_2018.pdfIn PDF document text
    • https://s3.amazonaws.com/fopalew/hemangioma_liver_guidelines.pdfIn PDF document text
    • http://janosunitemixe.epizy.com/riditonitavugutokigazi.pdfIn PDF document text
    • https://s3.amazonaws.com/batiku/cheap_thrills_lyrics_free.pdfIn PDF document text
    • https://s3.amazonaws.com/jizubisetebof/amazing_grace_citizens.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000128e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E3 4812 bytes
SHA-256: 8e3b8f9d407568faf541996ce2a9c8ad56285f1c814b30edfaaf4d1cce0cce76
font_01_sfnt_off0001395d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1395D 11728 bytes
SHA-256: ad2dd1cfd6535c77a2a0e448b32c9a1afdf962220f56e63f1dd3c5f3b6b3e704
font_02_sfnt_off00016168.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16168 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333