Malicious PDF — malware analysis report

Static analysis result for SHA-256 b387fd346151246c…

MALICIOUS

PDF

85.5 KB Created: 2021-06-26 11:06:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b8c94fb874506952936de3d134393e7f SHA-1: 30ee4b651a30b45a276ed5be6f8ffa22f042bebf SHA-256: b387fd346151246cf70d8efae77303d46a07488f54a90e5feb3b1fa2a7b27b97
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, which is unusual for a typical document and may be an attempt to hide malicious content or exploit.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://infrive.ru/uplcv?utm_term=atomic+structure+and+periodic+table+review+answers
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16070be985009f---28822440861.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/7c0d379ac8a62f4bb950c2f1a6a6a451/95982263029.pdf
    • http://kondicionery-lubertsy.ru/upload_picture/file/sasinavisevolan.pdf
    • https://coonvalleycc.com/userfiles/file/leturinelusepenikukuko.pdf
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/43116353841.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/4u9s8ppnheare1p4rbefugu9fv/1396744021.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/a40175072e20c65cd872150d824bad5f/45454319289.pdf
    • http://www.allatpatikapecs.hu/images/file/wodadalukorojolavugoxew.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160d2780e55f45---98126062601.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608693c3f13bc---jadebinamotilegejobad.pdf
    • http://rideco.hu/upload/file/ronoru.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/7289b4bdd0ebe03b6a155a4d62ed8c3a/zifireje.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/246ded79a530aa4faefec95a711be87b/88026417044.pdf
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/60654429118.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/fd8d533697ba2b4e32e2836ce7d17b5e/49192689911.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/d6cc3f7c90bb8cae04f39bc2a6e7e8b9/gegodufekobawusa.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a6d07e20e---98287536204.pdf
    • http://agnieszkapawlik.com/userfiles/file/fipapuzad.pdf
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607416b1609d6---xogujarevepipazajevi.pdf
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/n3j3c84m4ba20103e7ogb2gir5/17449672990.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/271ab82d23a358a77e5f11b16c55c23e/lutanomowotuxegobevad.pdf
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/97168201fe3dcde97b782e7040d42f04/farusupanaleri.pdf
    • https://bititechnika.com/uploads/file/remigu.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_off0000ea43.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA43 16792 bytes
font_01_sfnt_off0001025a.bin
9b213a6194c4fdd5b9bc4501983d600e0e2bdf57f448bd3873d47fa01f027702
pdf-font-stream PDF embedded font (sfnt) at offset 0x1025A 11048 bytes
font_02_sfnt_off00011bdc.bin
d6c4e5440622d9bbf7385a316e6bceed7ce47705f36d3897723d25b619a4d825
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDC 17100 bytes