Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0a16efd99c85014…

MALICIOUS

PDF

74.0 KB Created: 2021-09-11 21:45:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1dab4d88a85aa98108674f50658ec9d1 SHA-1: edc55b2dc86e71100e4be25b03af99c4b03f6dce SHA-256: b0a16efd99c8501426f3a8fd190763b1879a6d9c1f1e26fbd21a359054ebcee0
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to host many links on potentially untrusted domains. While no scripts were explicitly extracted, the presence of external URIs and the overall structure point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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 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 http://guojingmall.com/userfiles/file///80452665625.pdf In PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16138d67bbf034---siluvetidujiz.pdfIn PDF document text
    • http://xecuoihuyhoang.com/uploads/userfiles/file/99529010309.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/minatuvijodosif.pdfIn PDF document text
    • http://stl-hk.net/userfiles/25403431291.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/labaxaxidoduzizevagusu.pdfIn PDF document text
    • http://abwalabamaave.com/uploads/files/sitobob.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/fiwanidix.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///202191125830656.pdfIn PDF document text
    • http://canadianartistic.com/userfiles/file/66420297857.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/zamiwodibe.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/73870369027.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/80088585718.pdfIn PDF document text
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/zajawikebuzala.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/meniz.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/44925286654.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/tasiturokisusamagon.pdfIn PDF document text
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/60263600187.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/kajunujemivazubizamusibud.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/63699620209.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/e6fbdfa997593a23742a1fdd4b7da498/buremofobimir.pdfIn PDF document text
    • http://giaydantuongphongngudep.com/images/news/file/41688809635.pdfIn PDF document text
    • http://rakkhunnursinghome.com/user_img/files/zozumawojemulu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=national+treasure+book+of+secrets+putlockerPDF link annotation
    • 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_off0000bed5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBED5 16500 bytes
SHA-256: 5b5b70ab134839990a963909e10fdc98d63b5b3edc593b6586705fff3b099635
font_01_sfnt_off0000e977.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE977 10784 bytes
SHA-256: 2e10379417685ccf74ffaf4fc6ddf037cf29b4a710b4b361b8f0ac7b46c1dcf1
font_02_sfnt_off00010240.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10240 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1