Malicious PDF — malware analysis report

Static analysis result for SHA-256 4543fa9e099b96e5…

MALICIOUS

PDF

78.7 KB Created: 2021-07-08 01:21:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6d8188fb94bcaa1de8ac8a2a7bc6b00a SHA-1: dc2ccffee5a2a8537c2598de905d8ed253dc93f7 SHA-256: 4543fa9e099b96e5179d0a1011f4709a15ff11fc4e0c5db3f46d7b7c11a4608e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF containing embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the execution of malicious code or redirection to malicious sites, while the link farm serves as a lure for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b03ba3cfbdb.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb239a6058---norimuvolu.pdf
    • http://poltinik.ru/userfiles/file/29993478039.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/21046d91973d0317acf2feb91c2b949b/99096098722.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160b0207ee9ba1---bapobavozepak.pdf
    • http://thesciencenetwork.org/uploads/files/rosofifefuvovu.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608de875091f7---zowizase.pdf
    • http://orgue-chantepie.info/FCKeditor/upload/file/pekuwamaf.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609450ed4f4df---62285269459.pdf
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3c5081526---mofirumilukuvafagixovoli.pdf
    • https://pointvirgule.ca/upload/editor/file/89098605200.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/cf80c8388dd87926d4517f34cbf5f0dd/kivuwukedupuwilodaj.pdf
    • http://www.adarshvidhyasankul.org/userfilesfile/kizotegez.pdf
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/p2g4dv6bsof738oa009n5at5a3/sowutalinetugofiwokizuwi.pdf
    • http://slp72.com/clients/7/7b/7b902bee17765b19ebdde6030f24742d/File/mujadakazasu.pdf
    • http://euro-ex.com/images/blog//file/jefabopojiluwologavokefe.pdf
    • http://gunjanjain.com/app/webroot/js/uploads/files/93711832884.pdf
    • http://aliceinformaticasrl.com/user/pages/lifufedidifobezor.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095aaf2e0f0d---pagekinapikuvu.pdf
    • https://alakharia.com/public_html/userfiles/file/pexabezevufone.pdf
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/pj48khj22cb6o53ttgdanbf0hp/folibik.pdf
    • http://uppercanadatwocylinderclub.com/clients/877835/File/88401539272.pdf
    • https://novamakine.com/upload/ckfinder/files/47289784933.pdf
    • https://thietbidienmanhcuong.com/upload/files/ruluduxupuvojewe.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=people+daily+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_off0000d0e5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0E5 16792 bytes
font_01_sfnt_off0000e8f7.bin
76cc4b55a6f1265f07fbf4c350e9ca62c8ece55bab682eaeb5f23b5bc6e7dd4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F7 18160 bytes
font_02_sfnt_off00011728.bin
d2e0d083b33d98bbe75f0aea897f1602624915d6718222ece88c487b7c37d89d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11728 10136 bytes