Malicious PDF — malware analysis report

Static analysis result for SHA-256 761a508ddc5c8c42…

MALICIOUS

PDF

79.6 KB Created: 2021-09-13 22:48:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d3dac46cd7a39ff23b66ac5ac1357ed1 SHA-1: 6c37748f852892f5aed30ea6849b8b3c1df63940 SHA-256: 761a508ddc5c8c42dc13183bb6709cdebc9a133a8156123c93cdd307066925e7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The heuristics identified it as a link farm with numerous external URIs, suggesting a phishing or malware distribution attempt. The document body was unreadable, but the presence of many links to PDF files on various domains indicates a likely attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://rcot.by/pics/files/kujoxire.pdf In PDF document text
    • https://mimpiindah168.com/contents/files/28937429472.pdfIn PDF document text
    • http://roycraft.ca/userfiles/file/pavewax.pdfIn PDF document text
    • https://dm288.com/slicice/file/lirowepuxepero.pdfIn PDF document text
    • http://essiac.cz/UserFiles/file/27385940497.pdfIn PDF document text
    • https://noventa.cz/media/files/file/porufosud.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/53374422543.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/zoweraz.pdfIn PDF document text
    • http://vandientuchinhhang.com/upload/files/47248186851.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/kaxagofikipavugexifipofe.pdfIn PDF document text
    • https://rosycaffe.com/file/losasikinefutu.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16132091da0b31---favipaxujevud.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20210909201414.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/bizudabisafeje.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/87501528550.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/83649950131.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-1/20210901071323182507.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/fawemasavo.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/6203242156.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210904180655.pdfIn PDF document text
    • https://lyubomiradineva.com/files/file/78301618981.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/93738083919.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///48326423511.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/f5e7a2a90fc440c1e1c65cda6343e60e/lebojaruj.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/8862682089.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=write+on+pictures+app+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_off0000d4b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B5 17244 bytes
SHA-256: df038fe759e5196e1d84381725e2d5e98251862c3f8b58dcfc778c19b859b066
font_01_sfnt_off000100a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A2 10552 bytes
SHA-256: b9d9d7fc9deca1c5b995148bbf9d884a782863cde547d565baea85b3a1524378
font_02_sfnt_off000118d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1