Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a7fc79494cf3404…

MALICIOUS

PDF

79.3 KB Created: 2021-09-09 13:47:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a90e8fe6ce4b9e0c867b26c40bcd0e8e SHA-1: e8dbf16b9b553942b1c2f24c6aeaa333fb335627 SHA-256: 1a7fc79494cf3404ea2b5382e393be9f77274904e4bbca6fe75cf5ddd60ff0ca
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or redirect users to malicious sites. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133cf276f054---30474919546.pdf In PDF document text
    • http://nawoo.net/userData/board/file/sitowiferalajo.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135245bdf2b1---7643179687.pdfIn PDF document text
    • http://reklamavysocina.cz/UserFiles/File/xakoj.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/fivemurozelosilafufirojiv.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/kegunowufalepisuzame.pdfIn PDF document text
    • http://ckm-machinery.com/userfiles/files/76695163357.pdfIn PDF document text
    • https://intrastorg.com/userfiles/file/19781592469.pdfIn PDF document text
    • http://kmconlinecme.com/userfiles/file/29319004676.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/a188fb62bc3225c0f8dc59f1a5437779/bulirematuresilukukep.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/91035777884.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384ace8bfa8---wusokarebiluvifaximon.pdfIn PDF document text
    • http://arniuniversity.in/ci/userfiles/files/tojuratekasipakuzuwe.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/78659785599.pdfIn PDF document text
    • https://classoft.ro/userfiles/file/gukun.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/161326276509b3---xovikuvapesatuzidez.pdfIn PDF document text
    • http://fluitec.fr/ressource/site-image/files/dudofitemukululum.pdfIn PDF document text
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/91326490249.pdfIn PDF document text
    • http://www.heksan.com.pl/file/bodolip.pdfIn PDF document text
    • http://transcash.com/ci/userfiles/files/dogekijujumumatovegeguwar.pdfIn PDF document text
    • http://www.klimavill.com/data/editorfile/tiretefuvizupirif.pdfIn PDF document text
    • http://finara-v.com/file_media/file_image/file/18069119174.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=types+of+natural+selection+graphsPDF 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_off0000d31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31C 16556 bytes
SHA-256: 5bc47f2003cd0d0014d62aed10fa63774625cc6be69646c7069485d7d6cfa9b5
font_01_sfnt_off0000fe2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE2F 10936 bytes
SHA-256: e304274bd6c4433426ccafac1db1a6d5400328b9b02060b407f0aff7bc98b31d
font_02_sfnt_off0001178b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1178B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1