Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd1bae9c04265b89…

MALICIOUS

PDF

72.6 KB Created: 2021-09-13 01:11:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2dfaef93a81375738adf43eb8306636c SHA-1: 923944f9aaff4d08a53f62b392c82d335df594dc SHA-256: cd1bae9c04265b89ed3bad1b04fc029d5c24527c99bb92aa909b3e64eb039eeb
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier strongly indicated maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the suspicious nature of the URLs. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to a malicious intent to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 4

  • 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://catamma.ru/uplcv?utm_term=construction+simulator+3+download PDF link annotation
    • https://karolinanowak.com/userfiles/file/4433992155.pdfIn PDF document text
    • https://horkolas-gatlas.hu/ufiles/file/521823090.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210906071956.pdfIn PDF document text
    • https://vettercycles.ch/userfiles/files/94992831027.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/52893419003.pdfIn PDF document text
    • https://kaptenhoki.net/contents/files/22488137391.pdfIn PDF document text
    • http://stapper.de/sites/default/files/userfilesfile/sezevifomokafuda.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/64438142917.pdfIn PDF document text
    • http://teleserviciomalaga.com/ckfinder/userfiles/files/gejibizipovubavenitanida.pdfIn PDF document text
    • http://benevolo.it/userfiles/files/17089407690.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/nikufixulufusorasi.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/zivufef.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/41259371225.pdfIn PDF document text
    • http://dsagco.com/Upload/file/midibeg.pdfIn PDF document text
    • https://dolmalatrek.com/userfiles/file/wulavuguzijozalava.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/5517316608.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/9498449233.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/geponukefof.pdfIn PDF document text
    • http://massimobertoarchitetto.com/userfiles/files/40905678468.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/zoripotoja.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-7/20210907112330914486.pdfIn PDF document text
    • https://argumentua.com/i/file/nimajoweviruviroxab.pdfIn PDF document text
    • http://indel.sk/userfiles/file/6460161796.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/54531771477.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/perudukowilanizafosuk.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/6989682106.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_off0000b803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB803 16944 bytes
SHA-256: ccbba6437008ae65313177d8672ca50049748dca77e456ea94fa7c9cda9e907f
font_01_sfnt_off0000e385.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE385 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB9C 10788 bytes
SHA-256: e21e3e8c5754e7642b2dff4fcab069933f4269db2f74b0bebe8b0651f1353146