Malicious PDF — malware analysis report

Static analysis result for SHA-256 63651c646dc75035…

MALICIOUS

PDF

76.9 KB Created: 2021-09-18 07:47:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0ea3ec897c7fe39afae471662e1770f3 SHA-1: b477ffbcd6c691315bad46373f33caf99077a834 SHA-256: 63651c646dc750354dd29d7d844ba898d0ca0aa8fc2bd5b7d5c82ed478ebdd77
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous embedded URLs, many pointing to disposable hosting and employing UTM parameters, strongly suggests a phishing or link-farming attack pattern. While no scripts were explicitly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites, potentially for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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
  • 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://ketchas.ru/uplcv?utm_term=aha+telugu+movie+app PDF link annotation
    • http://thietbiotovn.com/Images_upload/files/livovokujuxirubefosizumen.pdfIn PDF document text
    • http://wangnatheater.bpi.ac.th/ckfinder/userfiles/files/kibefujopusujov.pdfIn PDF document text
    • http://touristclub.in/userfiles/file/zivutovebilozozute.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109141748444533.pdfIn PDF document text
    • http://reckdance.pl/userfiles/file/27102738865.pdfIn PDF document text
    • https://floridahouselottery.com/test/userfiles/file/kelixebonesonupiwedog.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/38903033982.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/41067619749.pdfIn PDF document text
    • http://sdsenlex.com/upload/files/94921145538.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1614081f59e797---lakovemuduvodegowukovasog.pdfIn PDF document text
    • https://duvarkagidierzincan.com/userfiles/file/40849984948.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/161309572189cf---waperegofinaxemut.pdfIn PDF document text
    • http://vatlieubaooncachnhiet.com/userfiles/file/14931115786.pdfIn PDF document text
    • http://chikatere.com/Upload/files/zidoladeni.pdfIn PDF document text
    • http://huiking.cn/uploads/file/08005654610.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/15746636796.pdfIn PDF document text
    • https://srsatta.com/ckfinder/userfiles/files/dirazowativ.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/fesitamib.pdfIn PDF document text
    • http://scro.ru/pic/file/zowavifapugis.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/golefow.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/negovizufivosiw.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/27177068484.pdfIn PDF document text
    • https://gallerylingard.com/uploads/file/julewuvatogoturifenira.pdfIn PDF document text
    • http://psn-monolit.ru/img_file/files/wirozedut.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/vesurutalog.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC825 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e03c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03C 10472 bytes
SHA-256: b9cc893d180d122bcca16d2f452100ea183d48d133be3207d803d862383170d5
font_02_sfnt_off0000f80f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80F 17672 bytes
SHA-256: fcae2bb9c25177887ef7617833c88968f49f0dc9ed695768097a504f9e39ece7