Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b595fca5b06ec79…

MALICIOUS

PDF

91.4 KB Created: 2021-09-07 19:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 62b2f7990a1222dfd55d76bc97eba5e6 SHA-1: 9b8c050dbd5f12fe9a2457d55541f45dbd035f46 SHA-256: 4b595fca5b06ec79b4a6b456c14d9c2bb8a33f2382af8b0c936a833b72c377b5
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, indicating a link farm or redirection scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, pointing to a tactic of using compromised sites to host or link to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 http://rilta.net/userfiles/files/fofuxidi.pdf In PDF document text
    • https://cleaner.pl/userfiles/file/80718265082.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/44596398744.pdfIn PDF document text
    • https://lacecinella.com/writable/public/userfiles/file/88680862799.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021051222325270554.pdfIn PDF document text
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/4679786443.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16099e2a95fedc---nuluzujunujolisuj.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c29f64bd318---1109507340.pdfIn PDF document text
    • http://daoltrading.com/userData/board/file/tujuketoxitux.pdfIn PDF document text
    • http://somersetcountybar.org/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27309426838.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fec1ab709d---87933210445.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/30758210138.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b6ae65dafc8---13155482227.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3089d0055---29985000000.pdfIn PDF document text
    • https://www.colours-of.com/wp-content/plugins/super-forms/uploads/php/files/d7ntj8ikm1a0t0m2eq08e1dtsm/63463858179.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16128df869cd9e---18636286764.pdfIn PDF document text
    • https://mraos.com/web/userfiles/file/75223206922.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078112ef402d---zujejumewolopapazidix.pdfIn PDF document text
    • http://studiosiciliani.eu/userfiles/files/79824192459.pdfIn PDF document text
    • http://cuatudongsaigon.net/uploads/files/85736283117.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/5d9f0bc9da089e635993e05368953586/govibov.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/08d23b28ed27adebe8d699f16c6b0da5/7346286929.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/fa74b1fdf2b58152be5cf132d9a45dfa/doverap.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/14e65a5fb9c8c92a5f59da6af599f68d/50909449937.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+calculate+valency+of+elements+pdfPDF link annotation
    • 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_off0000f8ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EC 20324 bytes
SHA-256: 4437edeabf691dd0aa9fed2b5117e7c0c017eee4cf00f5c731e9d63a8f028657
font_01_sfnt_off00012e1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E1F 10944 bytes
SHA-256: 782ac0149763354d43118dd2a53703595ff6747c9f516db3c614636dfd567013
font_02_sfnt_off00014793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14793 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1