Malicious PDF — malware analysis report

Static analysis result for SHA-256 d49a0ba5664fc06e…

MALICIOUS

PDF

81.5 KB Created: 2021-09-02 04:15:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 49f2eb75ae7297440c20b54c96f33f7a SHA-1: d13f45ffc558db150762bf2f6fbd8ab66a2fa6c8 SHA-256: d49a0ba5664fc06ea94055c6aa9895b1ab56aa7036d676bb15706b528af4f71d
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or other disposable hosting. This suggests the document is designed to act as a link farm, potentially for SEO manipulation or to redirect users to malicious sites. The ML classifier strongly indicated maliciousness, and the presence of compromised CMS upload links further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://medvor.ru/uplcv?utm_term=water+vascular+system+in+echinoderms+ppt PDF link annotation
    • http://neonatal-surgery.ru/userfiles/files/vejobufafugo.pdfIn PDF document text
    • https://pro-biomed.com/admin/userfiles/file/jojuwew.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610fd8d54dabd---wixenuvebebumilid.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/dipejalotozixemegozi.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/hhmsuthehfiudtbp7avj3gfhis/16652359886.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609823ab5f660---kogemipevibop.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/50690023943.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/giruvob.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/9r1f8dgvsnh05njkrhiaqtmimr/balitajurisejokejeka.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076f6850fe2e---77391461289.pdfIn PDF document text
    • http://herculesestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/19499114966.pdfIn PDF document text
    • https://bliznacite.com/files/zetisaritiwunow.pdfIn PDF document text
    • http://minhanh.com/files/lufapupowegididopatefaso.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/mubox.pdfIn PDF document text
    • http://dblbtech.com/userfiles/file/79896547286.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/63a84af8c6ebbb2698962dbfcf83d1ce/18576221189.pdfIn PDF document text
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/bibepobeduzideperusutizu.pdfIn PDF document text
    • http://tecresconsolidamentorestauro.it/fck_data/file/49591115551.pdfIn PDF document text
    • http://chanakyaaerospacedefence.com/userfiles/file/gokinesew.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/72cfcdbfb406c215411afc0ebff4ccf1/89584072888.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078bf9687b58---16297931604.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/57004013339.pdfIn PDF document text
    • http://ahsaipu.com/v15/Upload/file/2021514543587882.pdfIn PDF document text
    • 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_off0000d930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD930 11052 bytes
SHA-256: 08d03c0eef4852268d3af71f2047d7663d8a06713e3af1fd3e1c236b7a3274c7
font_01_sfnt_off0000f2c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ad7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD7 17360 bytes
SHA-256: 7aaba1a54f5a2b2760363835ea58dae7bafa244da72a65f197b99417484c40f1