Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c4ef805746421dd…

MALICIOUS

PDF

74.6 KB Created: 2021-09-24 11:13:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c710a39dd0d448231552d816bbb4c877 SHA-1: 27497b6301ebdcac13c3e71c79d868625e017668 SHA-256: 9c4ef805746421dd176802db7ad9ec884c209a1dfd583cc386965db661c18778
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file is a PDF document identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites or disposable hosting. The primary purpose appears to be directing users to malicious external sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://crysiq.ru/uplcv?utm_term=unity+android+local+notification PDF link annotation
    • http://fohow77.ru/upload/file/48552797076.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/jojawonukigisadewuv.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/99509643882.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/zukibuti.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/fivur.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/r4525fvk2ismna0kegjtdnagt3/kelumudirotemalejawe.pdfIn PDF document text
    • https://clap-bas.com/userfiles/file/koxipemokikuvup.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/99135281658.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/87879882172.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/59165419635.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613683137649f---19705594183.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/6367201195.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/f30883cdfcf17d9210289172ceb5ddb0/1960677945.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/bajoxizezupanutofupogam.pdfIn PDF document text
    • http://tehpromyar.ru/media/file/xudezuzabujed.pdfIn PDF document text
    • http://studiotecnicoarduini.eu/userfiles/files/6879035999.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/38499705425.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613acb04c1f9e---9537816522.pdfIn PDF document text
    • http://kant21.com/userData/board/file/70307016635.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147943991de5---35313896395.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/c016abb7043999bae8b93a78a6bc47e2/69537168423.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/27066715131.pdfIn PDF document text
    • https://dveropolis.ru/upload_picture/vokerogivomuki.pdfIn PDF document text
    • 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_off0000bc28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC28 10292 bytes
SHA-256: fb7620b3d2148e42609c018d66518f0f8d8adc716ed464813ad928b97b625202
font_01_sfnt_off0000d368.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD368 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7A 18952 bytes
SHA-256: dc1c077b7fd000fbb6dc18a31b0bcd42d8ef600ee8d8785b256c2a39debecb48