Malicious PDF — malware analysis report

Static analysis result for SHA-256 8939f6b6ff88e45a…

MALICIOUS

PDF

76.2 KB Created: 2021-09-26 15:33:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8e8dbbebe9146dc87aeee7ea9e3942cc SHA-1: 928e6d599b695ca515a43f7a18dde157d4c2dd5a SHA-256: 8939f6b6ff88e45a9d6eb882f808fac5836039341fd424a36d7dcae2f8dbd112
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many pointing to potentially compromised CMS uploads or disposable hosting, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://polletnv.be/uploads/files/38524835271.pdf In PDF document text
    • http://rsst77.ru/upload/files/nafirewul.pdfIn PDF document text
    • https://konzolstudio.ro/uploaded_files/file/1714060283.pdfIn PDF document text
    • http://think6.net/ckfinder/userfiles/files/20210925022352.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/84180512366.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/75135077311.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/46622239581.pdfIn PDF document text
    • https://eyescare.vn/app/webroot/upload/ckfinder/files/panitebepo.pdfIn PDF document text
    • https://rakowka.pl/userfiles/file/falagig.pdfIn PDF document text
    • https://hlj-vibration.com/uploads/image/20210902/files/20210902042052.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0f2636581---65982295079.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d48b27b6b3---53713945082.pdfIn PDF document text
    • http://goldmustang.ru/files/files/8227786276.pdfIn PDF document text
    • https://hmradiatoriai.lt/images/files/85701715199.pdfIn PDF document text
    • http://waycreon.net/bhaskar/yii/upload/files/roxorax.pdfIn PDF document text
    • https://springkasteelhuren.be/userfiles/file/fumenamiviwipasewomul.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/forodafonafuxexos.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/82005456111.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/55357213256.pdfIn PDF document text
    • https://riolisboa.com/images/ul_files/file/0GqHM7Qawvjp.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/0f1402f0fc43434128db0ab8b65f9f1c/vaxibosutewem.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138fb803b6bb---5609985674.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131062fc37cf---julinalotazifusu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+to+turn+off+notification+bar+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_off0000bec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEC6 19976 bytes
SHA-256: fbe4299f51382b99bcbb24ac431e1961d25ce58c102693b6d079a5b4155f88b8
font_01_sfnt_off0000f32d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32D 10440 bytes
SHA-256: 3655b9d7db5a75eec0d2b5736f407e4c0e8ccf7ee98ef34949b535d88e54394c
font_02_sfnt_off00010af7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1