Malicious PDF — malware analysis report

Static analysis result for SHA-256 137cabd270e4396a…

MALICIOUS

PDF

96.6 KB Created: 2021-03-16 16:51:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 21d55d0f929ab766aad3361c5323101f SHA-1: 9f4900a9051657d5be564e5230dc6d4aa27e6c2c SHA-256: 137cabd270e4396a23fb4fe273fa81105b0b26e55da15fa396dcef40731b5510
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm, with many hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO spam. While no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to facilitate redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://jottigo.ru/award?keyword=active+learning+cooperation+in+the+college+classroom+pdf PDF link annotation
    • http://tonerinkstore.com/grade_7_math_word_problems_with_solutions0ijtm.pdfIn PDF document text
    • https://cdn.sqhk.co/dixobiwi/ghKjhxu/work_cited_journal_article_mla_format.pdfIn PDF document text
    • https://cdn.sqhk.co/rekubapapup/jgiiiNx/zukofujibewo.pdfIn PDF document text
    • https://cdn.sqhk.co/nimuxugemu/8Cidoii/60708733656.pdfIn PDF document text
    • http://winefesa.22web.org/nitekerozavu.pdfIn PDF document text
    • https://cdn.sqhk.co/xawefigi/FCogjj2/11865366102.pdfIn PDF document text
    • http://fibipowokogo.sportsontheweb.net/bancassurance_regulations_2020.pdfIn PDF document text
    • http://sakulog.sportsontheweb.net/speedbit_video_accelerator_activation_code_keygen.pdfIn PDF document text
    • https://cdn.sqhk.co/timadupak/i5kfifw/branson_guide_top_things_to_do_near.pdfIn PDF document text
    • http://beamorem.com/cost_of_casio_edifice_wr100m0pil8.pdfIn PDF document text
    • https://cdn.sqhk.co/majumoros/hbIjjhh/mazerimorumi.pdfIn PDF document text
    • http://lamanixumerad.mypressonline.com/how_to_set_up_homeworx_digital_converter_box.pdfIn PDF document text
    • http://budofibo.mygamesonline.org/java_swing_gui_programming.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://c504e2ef-f928-4e80-b5b1-fc05046f432e.filesusr.com/ugd/247f25_4027f1db4f3a444786ebdfab5024d8d7.pdf?index=trueIn PDF document text
    • http://masagofoxinupad.rf.gd/55270743592.pdfIn PDF document text
    • https://37991ae0-d72b-4ccf-bf90-288dedd591e7.filesusr.com/ugd/041b56_75a968c948fc4d89b1c41a04ed54c889.pdf?index=trueIn PDF document text
    • https://f495c71d-628d-4070-9a3d-b699cbb46ba4.filesusr.com/ugd/d99ef3_8a9654066f5e46988ed5d26ca19b26dc.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_off00013c89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C89 5620 bytes
SHA-256: e99d0cadc25b96b4e79de3b6930089ed224eb54d32c60b84f3e0eb9664fe8d72
font_01_sfnt_off00014f7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F7C 11100 bytes
SHA-256: 98beecf8d76b4993869d7cb1b11732fb5d136d228450ec39f515a48f25bb2430

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