Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b4b16176c5913d5…

MALICIOUS

PDF

93.5 KB Created: 2021-09-18 11:45:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 789377635ea6066639fa4508b83c61f3 SHA-1: 7976db65011e71198f4a3679282b0f96d91b2202 SHA-256: 2b4b16176c5913d56794cfff102ef88a49b8e4a6c046feec47ece8b825c574f0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, a common tactic for phishing or redirecting users to malicious content. While no scripts were explicitly extracted, the presence of numerous embedded URLs, many pointing to potentially malicious domains, supports the attack pattern. The document body is heavily obfuscated and unreadable, preventing further analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://hattoco.vn/images/ckeditor/files/jojagujidurutevokorafuxut.pdf In PDF document text
    • http://omnoiptv.com/outscapes/admin/ckeditor/uploads/ck/files/linenidamo.pdfIn PDF document text
    • https://theelementrama9.com/userfiles/files/zowuzoforezumov.pdfIn PDF document text
    • https://ecohort.com/userfiles/files/1565994089.pdfIn PDF document text
    • https://sunkamalzemecilik.com/userfiles/file/18495098260.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/jegenuxenasowofafowo.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/27533689427.pdfIn PDF document text
    • https://jss-moms.si/upload/File/nudedelipizoduposapar.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/22822388146.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/xajolukerezopofozexef.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/39578947291.pdfIn PDF document text
    • https://idosekotthonaveresegyhaz.hu/files/files/lazepevigagapef.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/zixalabewa.pdfIn PDF document text
    • https://thefertilizergranulator.com/d/files/36685166208.pdfIn PDF document text
    • http://tomaszskiba.com/userfiles/file/40073774345.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/98236754548.pdfIn PDF document text
    • https://movimientofamiliadejesus.com/images/uploaded/file/28101891237.pdfIn PDF document text
    • http://hutbephottaihaiphong24h.com/upload/files/nizamewotodajulukomowige.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/926141f3ff4ccb4ce624cd6bda5c7ebb/firawuw.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210908232443.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/kifuzogilupiwa.pdfIn PDF document text
    • http://thewhitmerlawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sinuforezabipekagozapiboj.pdfIn PDF document text
    • https://quanticabtl.com/cms_2018_quantica/sgi_userfiles/userfiles/files/kanutegatogigumabixedatax.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/batef.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210908022531.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=dictamen+pericial+en+criminalistica+pdfPDF 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_off00010736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10736 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F4D 10664 bytes
SHA-256: 3e9de63720287a41e937c0810319a9b0f797e460566e6e3fecc21a0aa978be8f
font_02_sfnt_off000137b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137B1 18884 bytes
SHA-256: 02cd2555a41bb050263e593b7192194c4536746113664aa3377bda46015f2bfc