Malicious PDF — malware analysis report

Static analysis result for SHA-256 a865ec7c666dc0fa…

MALICIOUS

PDF

72.5 KB Created: 2021-04-14 22:41:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 8a7144c6c491da0e956ca467941f119f SHA-1: e34ffbba784d6181a6ddc22c8c1fd57b7705df61 SHA-256: a865ec7c666dc0fa4ff3207f64bab98c6fe9cca938d7806e41b553bd47674f97
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, indicating a link farm designed to manipulate search engine results or redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external URLs are indicative of a malicious document, possibly leveraging embedded JavaScript for redirection or obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://resalured.ru/strik?utm_term=myers+ap+psychology+textbook+pdf+1st+edition PDF link annotation
    • http://serarudipiwuvon.mypressonline.com/wazijedikabivuzod.pdfIn PDF document text
    • https://cdn.sqhk.co/penuvipaw/i58xhcA/vaguvegejewu.pdfIn PDF document text
    • https://cdn.sqhk.co/noneniwetav/Xibijjc/46878211935.pdfIn PDF document text
    • https://cdn.sqhk.co/narobalof/jdhbwjc/63724943605.pdfIn PDF document text
    • https://cdn.sqhk.co/datawafag/4m8v5gf/88517638620.pdfIn PDF document text
    • https://cdn.sqhk.co/kamupudoro/tyhfnje/social_detective_app_free.pdfIn PDF document text
    • https://cdn.sqhk.co/felolavap/QigL91C/67426489837.pdfIn PDF document text
    • http://leledup.mypressonline.com/disomudebadifox.pdfIn PDF document text
    • http://xademubizu.sportsontheweb.net/defuzilutopomedolopusuf.pdfIn PDF document text
    • https://cdn.sqhk.co/zetoreli/gfhLXDk/netflix_christmas_movies_2019_list.pdfIn PDF document text
    • https://cdn.sqhk.co/pepupiribojo/dgflbjc/best_fantasy_romance_books_on_kindle_unlimited.pdfIn PDF document text
    • https://cdn.sqhk.co/gajalalike/cJgOBje/ato_institucional_5.pdfIn PDF document text
    • http://sewukagazub.mypressonline.com/64899039398.pdfIn PDF document text
    • https://cdn.sqhk.co/dutedape/Omiaxjd/8140166857.pdfIn PDF document text
    • https://cdn.sqhk.co/buzomesil/jdkakid/i_want_to_learn_chinese_language_online_free.pdfIn PDF document text
    • https://cdn.sqhk.co/desiruzag/fHHjfhd/auditor_contravention_report.pdfIn PDF document text
    • https://cdn.sqhk.co/bosareke/geCheMB/lopuzupevekedubewo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://23da7c74-6e14-424a-b22a-901aa35eafb1.filesusr.com/ugd/9cc572_9d8cce00961a4999b57b4a2c4d9037c0.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fekazudabo/how_to_pair_my_bose_headphones_to_my_tv.pdfIn PDF document text
    • https://s3.amazonaws.com/gimisorixosu/38699187314.pdfIn PDF document text
    • https://s3.amazonaws.com/garorowa/1500_frases_mas_usadas_en_ingles.pdfIn PDF document text
    • https://13cfbe10-32e4-4d7a-9072-8dbd3280e6b8.filesusr.com/ugd/994e9e_dcc7fa5fba7e48eba56cf386a414e4a6.pdf?index=trueIn PDF document text
    • https://8eefcaf3-52f5-4123-8be5-b1f0aaeea45e.filesusr.com/ugd/1d3654_f4e7250b7f944c429e19cbbbb91e46e1.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_off0000db89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB89 5848 bytes
SHA-256: 6a7dc0a55fd50c0d9d98993dcf2057024f289890498f089c16f8088d4d1fbeff
font_01_sfnt_off0000ef86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF86 10784 bytes
SHA-256: 077300a1af4f42beb571627b07c59b26efec5a7914c4523db7a97e3023ec2737