Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9f7be85400fe7f…

MALICIOUS

PDF

69.9 KB Created: 2021-03-28 20:31:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: e6904f08e5771bfe3386c02a41cad389 SHA-1: edc4fb67499c5b9244c6aee64f7c0ee71140c728 SHA-256: 4c9f7be85400fe7fb4c9c50bd9f60eb5ffeff55fb0ce99629bd2a6b82a91128b
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://vilenefex.ru/strik?utm_term=linux+programming+interface+github PDF link annotation
    • http://pijevovonojatev.iblogger.org/hssc_clerk_admit_card_2016_link.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379491/normal_5fe59b5b74f0d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410952/normal_5ffe5f935dae2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485451/normal_5fe90163c18ed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461761/normal_6033a3b8bb700.pdfIn PDF document text
    • http://kugezuxabomo.iblogger.org/lofeforajizowowirazutap.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419198/normal_604f2fcce971e.pdfIn PDF document text
    • http://xexisutufas.iblogger.org/88801260472.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://1c985592-4fe2-425a-b8d2-7dc24782370c.filesusr.com/ugd/a13bc2_b1d01eb3ea6b481d93159e9b5d71a74c.pdf?index=trueIn PDF document text
    • https://f3dbd103-cf2f-44fc-b0ad-c9004dc38af2.filesusr.com/ugd/1f2646_d015b7c261fc46c9a7e669bbae3a52cc.pdf?index=trueIn PDF document text
    • http://ninefaniki.rf.gd/the_duchess_of_malfi_characters.pdfIn PDF document text
    • http://gakinodimojulat.rf.gd/pdf_file_convert_into_word.pdfIn PDF document text
    • https://8772a198-af03-49ef-8724-5feb7546cb8a.filesusr.com/ugd/436f04_dbb5282746ec4dce8bccb0ee2d556715.pdf?index=trueIn PDF document text
    • https://fec450ea-b80f-4746-b851-35139cc02de5.filesusr.com/ugd/53a83b_71baf8da9f38425087cafc5d873ab803.pdf?index=trueIn PDF document text
    • http://xafinoligu.epizy.com/kinilaposedeg.pdfIn PDF document text
    • https://584dc5e1-4449-4bca-b3d9-d0e1fa08a972.filesusr.com/ugd/185caa_52a573994dc348968aa7ed7c7857fb62.pdf?index=trueIn PDF document text
    • http://wutivufugisev.epizy.com/mozudarutinazudujuka.pdfIn PDF document text
    • https://9334512a-4df1-45dc-8804-f0fa1d9e2a3d.filesusr.com/ugd/9466eb_88ab4196be9346a4807fd1097fd78b03.pdf?index=trueIn PDF document text
    • https://ff5d1526-1eb9-447d-8915-67ca9933f1b4.filesusr.com/ugd/9565fd_af1de5136f5e444c80231e4974a7ce77.pdf?index=trueIn PDF document text
    • https://e1d5fa5a-667c-4d22-bb72-2ec96b4ed0f7.filesusr.com/ugd/01f30d_356b4faf983443409a8a88df8e9cc50d.pdf?index=trueIn PDF document text
    • https://d4508431-0eee-4913-ac2a-2ec907ed9b18.filesusr.com/ugd/12daa7_3ffaa35cc2c047ef968c83cc6584eccf.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cbb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB3 5368 bytes
SHA-256: 23e9092c0095472aa34661248e422db6d10e96a084eca1f4f0266bf28e906fe1
font_01_sfnt_off0000ddd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDD5 1936 bytes
SHA-256: cf50d13c5c21d2e34fba0d9dd21119d4839fc35fdaebfe62cbacf51850cc328d
font_02_sfnt_off0000e713.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE713 9656 bytes
SHA-256: ae77bc0183e329839deaced1512951ccc0cedaae75f32463ec14123f8d318eff