Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb87491145bd6380…

MALICIOUS

PDF

80.8 KB Created: 2021-09-18 22:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3a6824aa1422307a4fb8d9dac6291e94 SHA-1: 5fe729000768921a5b065625fd3475f22b2e82d2 SHA-256: cb87491145bd6380e3ede231ff5783204e653b81a34982e3b433332f2eb3094b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as containing a link farm and was detected as a phishing trojan by ClamAV. The ML classifier also strongly indicated maliciousness. The embedded URLs point to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious content or downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://webkapper.nl/ckfinder/userfiles/files/14589523820.pdf In PDF document text
    • http://www.gonouvellezelande.com/files/77251186679.pdfIn PDF document text
    • https://www.willmarshelter.com/ckfinder/userfiles/files/46467892275.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/61ddef1ce17e9428eb70c99b0511f325/mikidomonoziteb.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614118f756985---30998902641.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/15286919691.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/6da3260944196da518448386c09a360e/56892458491.pdfIn PDF document text
    • http://swaptoys.org/ckeditor/uploads/files/vugemusipoxo.pdfIn PDF document text
    • https://alhasooncorp.com/Files/files/52270620588.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/6862963769.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021090717521573499.pdfIn PDF document text
    • https://propactionvehiclesuk.tv/userfiles/files/80732645315.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210908090339866.pdfIn PDF document text
    • http://yogo110.com/userfiles/file/57084384186.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/sifajubefitavukokadetijo.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/99138793225.pdfIn PDF document text
    • http://szm.hu/userfiles/file/tilexijivopa.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/18416174556.pdfIn PDF document text
    • http://generoussecurity.com/uploads/dugezusalixateg.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16141a8018ac61---rerexevigamevoxegixe.pdfIn PDF document text
    • https://smartech.lv/sites/smartech/uploads/documents/files/mebikarebubo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=download+we+sing+apkPDF 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_off0000d663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD663 10548 bytes
SHA-256: 8ef7d1b03b8e87ed4f5b0d1c7ce0fe307bfcdafab280657cf14933c3cf0e56e0
font_01_sfnt_off0000ee54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE54 18336 bytes
SHA-256: 8bc2e30da33136e4819101d840d8eb5d8d03c7bcbbfc211966ac0cf8a3d4f5bd
font_02_sfnt_off00011e21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1