Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d4f94166008377…

MALICIOUS

PDF

86.5 KB Created: 2021-07-14 00:01:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0356e162a677a7f1c8d6fc7b8fffd468 SHA-1: abd6591176b3a08e9fc4532d7ed6105150617d74 SHA-256: a8d4f9416600837757eb1cc6bdbfd963a24df363ba93c83e9824b9f2f39f507b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://inwebjor.ru/uplcv?utm_term=platelets+down+means
    • http://abwmountvernon.com/uploads/files/tunokubesitukukobakod.pdf
    • http://rentbucharest.net/images/userfiles/2824966657.pdf
    • http://russia-ex.com/98399357985.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/c811ef39395d008980c8c0381fb516d1/xotimusujale.pdf
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/7us5qv8e4orbvntvbg8973mb8m/xerelabepevumukog.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/u7o2ubhp62a0og04brga2jc7ns/40869020218.pdf
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/904509fc9d16fa0adfd0c73135e83d75/13377199533.pdf
    • http://agt.es/files/galeria2/files/94186466592.pdf
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec7b6362c6---gapebigirabib.pdf
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160bb8fb2a5a89---73149606687.pdf
    • http://aep-tc.com/cache/fck_files/file/pejenovojedepimex.pdf
    • http://changju-hotel.com/CKEdit/upload/files/dakovopirulomufunuwuji.pdf
    • http://fsanaq.com/upload/file/210623002936330126m7zhwd3d6b28.pdf
    • http://dichvuhangngay.vn/uploads/image/files/kazetimegemoxowax.pdf
    • https://roweryelectra.pl/app/webroot/uploads/file/16220166584956.pdf
    • http://pallenberg-busreisen.de/uploads/files/sogukuvewa.pdf
    • http://backkwang.com/userData/board/file/domokasavulugezag.pdf
    • https://ltssinternational.com/res/wysiwyg/file/59495832667.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/krr9e821uhlfmb84nviupj32g1/sopitenisa.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160e9061b5ffd8---migoxumafafekelume.pdf
    • https://airflow-skateboards.com/userfiles/files/puzuzototapobulig.pdf
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/s7h9fc7h8flkkhg2ug0ek71o3m/12407324707.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160a53ab1d814a---rojupotiwusevekefugavemi.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_off0000f18c.bin
100ce0b13a68800cb8d63d95b03adc9d78e32026a912dc3258d51f773343cbd7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF18C 10304 bytes
font_01_sfnt_off000108dc.bin
efbdda0cc7f8ff0863ed7a46cc36028a4787212e81f00bc00be7081c8536c0de
pdf-font-stream PDF embedded font (sfnt) at offset 0x108DC 16908 bytes
font_02_sfnt_off000134d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134D0 16792 bytes