Malicious PDF — malware analysis report

Static analysis result for SHA-256 25f9ac2dbc2976d1…

MALICIOUS

PDF

82.8 KB Created: 2021-06-28 23:29:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 54207931e8fe8e316651d92909890fc0 SHA-1: 9dff4aab1b88d9532d3a9e2fbe8c250ac993d92a SHA-256: 25f9ac2dbc2976d1db21c732ba0dec030845e284f15e93058f4dd4342d1a126c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm or redirection scheme. The ML classifier strongly indicates maliciousness, and the presence of embedded URLs points towards an attempt to direct users to potentially malicious content or phishing sites. No scripts were extracted, but the overall structure and URL distribution are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://laborke.ru/uplcv?utm_term=converting+pdf+to+ocr+text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/33834c98815e22224a9f79fb68dece94/76789281950.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/tqua5rr5lv3fpi74j9ub776m21/93624639306.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607efb5bb1ad7---lirawubus.pdf
    • http://backkwang.com/userData/board/file/34136077365.pdf
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1606c743b10fc4---19885223728.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070025135db6---vusemutu.pdf
    • http://gernano.eu/gfx/userfiles/files/35025322236.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8330d6e4a---19461357656.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f41d6262f19e1164943ceb59ff7d94fd/mawivofo.pdf
    • https://tskrea.com/userfiles/file/jaxosu.pdf
    • http://osc-pribor.ru/products_pictures/file/20808762698.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce6b8d6093---siwijegepejap.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/obk9p0sc79e7v1rsntts75c382/47480651140.pdf
    • http://promador.pl/userfiles/file/4651623527.pdf
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/a89fb18db4888231389a54453299b6bd/36516323148.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc53203201---49636321595.pdf
    • http://ghalemdi.com/userfiles/file/mudekalavanopo.pdf
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/11vpqvait9d8f6226ccddg1ci7/zijaximivamid.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947c2d5d47b---29282089322.pdf
    • http://guides2alpes.org/uploads/file/resupulokak.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608604429602e---86703700847.pdf
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/235d6e4e1639150ae43fc06caff2a56e/dikokavowi.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_off0000e2b1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B1 16792 bytes
font_01_sfnt_off0000fac8.bin
6facf16dabeb69272c860d898d0d691ef9e39053184e5a4ec012b4c4f02a9506
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC8 10620 bytes
font_02_sfnt_off00011308.bin
a4e8813796ed7fdc4b79494d9a640ccfc24d46f0bb9fb41d2ad988bbb71edf48
pdf-font-stream PDF embedded font (sfnt) at offset 0x11308 16576 bytes