Malicious PDF — malware analysis report

Static analysis result for SHA-256 521774eab00fd8d6…

MALICIOUS

PDF

85.2 KB Created: 2021-07-02 05:54:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d9b1ee4ed429d06f8627df3b36fdd874 SHA-1: 24c8cc52ccf7cd69db2d36a23727eb64fdecc1e1 SHA-256: 521774eab00fd8d6f74917b046f5d529215b452be8f79bcb3aa0267d62f84784
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://krisoc.ru/uplcv?utm_term=free+robux+2021+real
    • http://tradeweb.es/userfiles/file/vetunupasexudageg.pdf
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/b43162ee576293454aa881b972452e18/64683884307.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/ccaa31ba18f030304523e44d7d746861/zajisatoduxikofavefuwuxub.pdf
    • http://dlevitin.ru/fck_editor_files/files/57067169572.pdf
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/32f93004b0cd916440727a45e61d9e45/totunexigofilot.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/15696130727.pdf
    • https://jagominum.com/contents//files/78694871483.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607100f556b9f---mijijeg.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/ubid9uss6vt1naou7dah59bcj5/tatuwukamagatigokabes.pdf
    • http://yngc.ru/admin/ckfinder/userfiles/files/patef.pdf
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608358755e3b7---niluwipubazowelojipudaxe.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aecb8aa1d54---20646064059.pdf
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a431464e91d---nufokilajejadenoba.pdf
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/4ca0277c825929293f394ad4d8aba2dc/30593630902.pdf
    • http://theleadershipworks.com/PO2/UPFILE/userfiles/files/37710742070.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077dea16e436---53517007681.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc7764992fc---malexizezezuniselelewow.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c42d384f61---21698615390.pdf
    • https://medtek.vn/storage/file/namuxe.pdf
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/d935f6ed87e9e3e6a4195ef3d1eebd12/71405735666.pdf
    • https://fablab808.com/nbloom/fckuploads/file/48310913852.pdf
    • http://snotlicker.com/clients/10243/File/pasexesozubu.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079559027148---81472569809.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c13aa75187d---4539644400.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea23.bin
c79c69a9874fd79d98c58cbbb956aab4075184bd19cfdd2232ae6591e50a7bba
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA23 10252 bytes
font_01_sfnt_off00010160.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10160 16792 bytes
font_02_sfnt_off00011972.bin
f820c1c6ddc8b2ebbd50378195e9c743f3c32e18b4b1991494bddab3d371f622
pdf-font-stream PDF embedded font (sfnt) at offset 0x11972 17444 bytes