Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd85bdd8760de0e6…

MALICIOUS

PDF

84.7 KB Created: 2021-04-08 01:49:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 57ff7f552a85a1752a69d7a05efbad1a SHA-1: eca015bbb775d32e496627a2b7c2fa761fc24765 SHA-256: cd85bdd8760de0e6c07e7f46dbdd2e83c8c177f7604dd4b57c8b7fa7cdf83e82
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document exhibits characteristics of a link farm or SEO spam campaign, with numerous embedded URLs pointing to various domains, including known redirectors and disposable hosting. Heuristics indicate a malicious redirector link and a link farm on disposable hosting, strongly suggesting the document's purpose is to drive traffic to external, potentially harmful, sites. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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 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.
  • 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/123?utm_term=best+android+phone+camera+budget In PDF document text
    • https://cdn.sqhk.co/dokadajij/Biaii2H/picture_quiz_with_answers_ppt_download.pdfIn PDF document text
    • https://cdn.sqhk.co/mukujoripu/mggh7jg/magomumori.pdfIn PDF document text
    • https://lufapaxate.weebly.com/uploads/1/3/0/9/130969762/5e2d9bfd60f96b.pdfIn PDF document text
    • https://cdn.sqhk.co/wemitupu/GA7je6w/petrochemical_engineering_salary_in_nigeria.pdfIn PDF document text
    • https://vamabeloketofip.weebly.com/uploads/1/3/4/3/134344852/leweviralasegowo.pdfIn PDF document text
    • https://cdn.sqhk.co/ravuviwidi/jft4ju3/buggy_racing_south_australia.pdfIn PDF document text
    • https://lodikesilir.weebly.com/uploads/1/3/4/8/134868057/tonaxurefumiw.pdfIn PDF document text
    • https://cdn.sqhk.co/pawekenu/heihchj/block_3d_game_download.pdfIn PDF document text
    • https://riwaxetonebena.weebly.com/uploads/1/3/4/3/134363930/suxixobajowu-lomiva-nolujomewumirax-nexuji.pdfIn PDF document text
    • https://zulevoto.weebly.com/uploads/1/3/2/6/132696122/6cc22a.pdfIn PDF document text
    • https://morogixifidogaj.weebly.com/uploads/1/3/4/4/134497599/basinexuzadi-jatidit-kiwenodusabugu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://lexawelezalum.epizy.com/formal_clothes_l_g.pdfIn PDF document text
    • http://jepameji.rf.gd/song_of_solomon_2_10-16.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5cb958c6-eca0-44a0-8dfe-df4679228b2f/solar_system_word_search_online.pdfIn PDF document text
    • http://dizoran.epizy.com/92032943430.pdfIn PDF document text
    • http://pumuroxojab.rf.gd/sawoweguteziliweduvizib.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8248511e-c0f7-4a5c-86df-4ee9ece9d6e7/a_confederacy_of_dunces_chapter_5_summary.pdfIn PDF document text
    • http://lesesopexapawu.rf.gd/farifigegizezipenujebufix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/edbe1269-ff08-4d2a-8110-097c74450999/28137850805.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f59463f1-acf1-4ba7-b1d1-0d94b7ced8ae/reflexive_verbs_in_english_exercises.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/06ae547f-0a98-447d-8685-8106a2d07379/65826002079.pdfIn PDF document text
    • http://lunupoxupa.rf.gd/simple_data_structure_programs_in_java.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_off00010d3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3C 5644 bytes
SHA-256: 0c7e7c8c57f49d6a8ee38c12e9c13a23b8ef33fcc4f9682184ff7f3631d4a902
font_01_sfnt_off00012040.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12040 11080 bytes
SHA-256: e7d84461c56a6c6b07fbdf2b343a0ef3f4d2810ffdfbfc7eec544322c379d80d