Malicious PDF — malware analysis report

Static analysis result for SHA-256 6bb384c90bf17f4a…

MALICIOUS

PDF

92.8 KB Created: 2021-09-13 16:11:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 904b203f1771dbb2022ddc08260ecb0d SHA-1: ce82a2e9db9300a29e85787a92b4b854dad5c79c SHA-256: 6bb384c90bf17f4a118b456b22b17cc43322b32b8be9b7ac32036f7673e35cc4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a high number of distinct hosts, reinforcing the idea of a distribution network. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggests it's used for initial access, likely via spearphishing, to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://pune-india.info/userfiles/file/gimude.pdf In PDF document text
    • http://twtqedu.com/userData/ebizro_board/file/50311055616.pdfIn PDF document text
    • https://unosms.us/userfiles/file/pakunupip.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ccd471fd4---96160297032.pdfIn PDF document text
    • http://carmakers.cz/userfiles/files/75541341424.pdfIn PDF document text
    • http://pressvaluation.net/FCKeditor/editor/filemanager/connectors/userfiles/file/39861506264.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/79430936398.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/91999115312.pdfIn PDF document text
    • http://kaies.cn/upfiles/file/5039949542.pdfIn PDF document text
    • https://rcot.org/userfiles/file/18623578674.pdfIn PDF document text
    • http://interstroy96.ru/uploads/files/96569726983.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad810d3811---finekojira.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/fopuvusewin.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/fiforafomezizabo.pdfIn PDF document text
    • http://yujinpharma.com/upload/files/foxugavulajazupi.pdfIn PDF document text
    • http://pi-consulting.ch/download/vipaxekira.pdfIn PDF document text
    • http://flairpens.ru/uploads/files/19086986536.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/mupivefuvux.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/magiditoj.pdfIn PDF document text
    • http://grandfiltr.com/files/file/31044598143.pdfIn PDF document text
    • https://myclubowners.travelenvogue.com/userfiles/files/42386674570.pdfIn PDF document text
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/4258361125.pdfIn PDF document text
    • https://netiko.ge/img/Data/file/fexiwigofizegozanadere.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/mifanozudakurojiradabo.pdfIn PDF document text
    • https://chezgregoire.fr/userfiles/gonukewejiwiwi.pdfIn PDF document text
    • https://marljivo.hr/userfiles/file/11338550160.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+change+app+grid+size+on+androidPDF 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_off000103c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDB 19048 bytes
SHA-256: 8f100402c94735572b62107d3ce240eafa027a967f9c913029a420a998246aeb
font_02_sfnt_off00014ca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CA7 10884 bytes
SHA-256: c6c80be9c4f15d8848c49b000449d3c484423ee852f65c10441f90296404699c