Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5b3dd599d11b991…

MALICIOUS

PDF

82.9 KB Created: 2021-07-03 17:53:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b999c71d0155cd3c72ffb0f6692a939f SHA-1: 6cc0aab0267c341dc9ca5568a38467d3a8710677 SHA-256: d5b3dd599d11b9913caa70d019938782be459bf053f8cd0ab4648dd444486047
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting domains, indicative of a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is used for malicious redirection. No scripts were extracted, and the document body was unreadable, but the heuristic findings clearly indicate a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://garglob.ru/uplcv?utm_term=adjective+suffixes+pdf
    • http://imbirimbir.ru/files/48913016370.pdf
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/vk52dapeblvp68utdmrsdh3jqo/36927207179.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160745a9e3ffef---4331984332.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3ac5057c6---fotuwotekuvivedumubilez.pdf
    • http://akicgiyim.com/userfiles/file/jofumovezedajomit.pdf
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/iv42dd4pdklr1t9lj42jksa88u/pipesudirakepafizasim.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9b9bb54ef---91263917198.pdf
    • http://uk-finansist.ru/userfiles/file/wifiwamesoporonufatasuwa.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a022256751---26342159524.pdf
    • http://maskaevlawyer.ru/userfiles/file/givutewilu.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/cfcf70b7a01a8c0a67997e96e16654b4/65523583155.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/2skpot7c3ggnq0unfqje2m73ot/favojabotula.pdf
    • https://a2designbg.com/userfiles/file/87092679830.pdf
    • http://dabaizhongxue.com/upload_fck/file/2021-5-17/20210517221229747464.pdf
    • https://euroroma-bg.org/files/file/41608833579.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f62b346e3---nopakebiluwexiginatijemi.pdf
    • http://henrycrawfordreunion.com/clients/1/19/1929e20d1ffebcad6d8b2a659e9c170d/File/tixalevuvan.pdf
    • http://ibb-online.ru/f/file/peboworedifovigelolajow.pdf
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/joguketuxaso.pdf
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acb6c2cbf96---80423800315.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a23f79da702---texufaxinedux.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_off0000e3bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3BB 16792 bytes
font_01_sfnt_off0000fbcd.bin
0dded94b91d47eea80fd5e5e661ecaa3cfbb8bab8583bd2a617d335827ee1515
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBCD 16580 bytes
font_02_sfnt_off000126fd.bin
84d615f5554908410adbf1c90e8535a8dddf728cb103dd0620db51cb6044a8a6
pdf-font-stream PDF embedded font (sfnt) at offset 0x126FD 10460 bytes