Malicious PDF — malware analysis report

Static analysis result for SHA-256 f20e781aec7e75c4…

MALICIOUS

PDF

74.0 KB Created: 2021-07-02 04:22:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b85f6cad7f184cb389473e752cd8fc1b SHA-1: 3b700ca1559769fa97e77d8a57f5a4f8336a4261 SHA-256: f20e781aec7e75c463419c5571ed04df72e75c5c80bafefc31d3a30a2370db98
96 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple compromised WordPress sites, which in turn host other PDF files. The ML classifier strongly indicates maliciousness. The primary attack pattern involves luring users to these compromised sites, likely to download further malicious content or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/2f14cfc27e4c4fc40359dc1610470776/23724886560.pdf
    • https://amatnieks.lv/pictures/image/89718197477.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/c5566488a81b6a85f4f784a50ee7a49b/jeramupegusi.pdf
    • https://dienlanhhonganh.com/images/pic/file/57306079361.pdf
    • http://watthaistuttgart.de/userfiles/file/disilakos.pdf
    • https://argumentua.com/i/file/sujejofugofe.pdf
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/e44e98506a5bf03ec580c44c7f645dca/juzixipale.pdf
    • https://whatproperty.ng/ckfinder/userfiles/files/wikokepuvodevijusegaxina.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160d26af61ca44---40952624772.pdf
    • http://assessmentinsight.com/ckfinder/userfiles/files/zopibaguziwi.pdf
    • https://deniz-sogutma.org/img/userfiles/file/zujofovezinewefi.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a00c24acc27---16835817424.pdf
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/154361d533f1074bcee7ffff781ac9f0/mutumokabe.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/be509ab3e1408880d49429a742548d42/14415757714.pdf
    • http://mosjob.ru/images/file/27327988716.pdf
    • http://blackshirts1962.com/clients/f/f2/f245580d3072b78cda2271cf7a7e3f61/File/jibiw.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c43098178e7---vojijolusiwakoxixajevila.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/8a24e2abb38517bb54642b9d1cf8fd47/90707010904.pdf
    • http://thrifty-uy.com/files/others/xunexezazev.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609a639d7be10---41625796182.pdf
    • http://red-persimmons.com/upfiles/editor/files/74567814078.pdf
    • https://argentinaproduct.com/ckfinder/userfiles/files/duduzamezukowosopilabo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=fat+jack%27s+tap+house
    • 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_off0000bf37.bin
571bb6d1d434617458da83dcd08f6a86e9d8ccc714997dd23f7c3621e288f2ed
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF37 10460 bytes
font_01_sfnt_off0000d737.bin
61d6422a52a82c2510c4f7e01e296e4585beaa982961b9372637b92304b7d7ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xD737 16800 bytes
font_02_sfnt_off000102ef.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102EF 16792 bytes