Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca11f85b69cf6fb8…

MALICIOUS

PDF

69.8 KB Created: 2021-09-29 14:26:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 19bb89bf63e9e7105f9bb252e2dcbee8 SHA-1: 0b883cd4559282d7fc2a59411974f27d9ee7b705 SHA-256: ca11f85b69cf6fb8b28345e2640c86abe1b6827c543bfef996e2be73e149c49b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also features a large number of external links, many hosted on compromised websites or disposable domains, suggesting a link farm designed to redirect users to malicious sites or download further payloads. ClamAV detection and ML classification strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://irlanc.ru/uplcv?utm_term=screen+mirror+android+to+pc+via+usb PDF link annotation
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/d0e6996425d90c1be97d08da908818df/bilalunu.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/16131ba0d8341d---zulaf.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/titavatererutetimam.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/finobodupiwakemuxugur.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143874606635---finagubesojavenowonuj.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b0a2931297---96421509498.pdfIn PDF document text
    • https://gencatakan.com/upload/file/todafeb.pdfIn PDF document text
    • https://woft-dining.com/webroot/editor-uploads/files/xasosa.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/8964645770.pdfIn PDF document text
    • http://struttur-arch.it/userfiles/files/49245729438.pdfIn PDF document text
    • http://sov.tranovice.org/webpagebuilder/ckfinder/userfiles/files/1182467673.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/ninukadozun.pdfIn PDF document text
    • http://jfhconsultancy.nl/userfiles/files/54856768962.pdfIn PDF document text
    • https://soudureornementalelauziere.com/upload/editor/file/74901078986.pdfIn PDF document text
    • http://onthebroadway.com/CPD/adminpanel/upload/file/lekabupa.pdfIn PDF document text
    • http://bluekeydigital.com/images/pic/file/wofeduwejolexomojexi.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/dotelatebija.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/mulunamovupigokituxog.pdfIn PDF document text
    • http://nirmalamathachurch.org/cms_uploads/image/file/tusegoridagud.pdfIn PDF document text
    • http://congluc.com/upload/files/xetopuvudopesisevavuvafo.pdfIn PDF document text
    • https://4cmedica.com/ficheiros_upload/file/sivotanaruxenipudovozun.pdfIn PDF document text
    • http://daieimotors.com/js/upload/files/35830844111.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/motivirugi.pdfIn PDF document text
    • https://abcoegypt.com/userfiles/files/244625525.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_off0000b0db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0DB 15628 bytes
SHA-256: 316f840c738d22202f742400c7d92e12b6bf2b1c6ceff96711549fa1491813bb
font_01_sfnt_off0000d84a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD84A 11012 bytes
SHA-256: d4bc46fc53f3739482f2bec0482fbd85a765bfdc0fb25c084c19c5bcbeb24908
font_02_sfnt_off0000f1a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1