Malicious PDF — malware analysis report

Static analysis result for SHA-256 db2c0d9b40bc1651…

MALICIOUS

PDF

75.0 KB Created: 2021-07-25 09:37:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fd9fae2e7401c2e320b0dad75358d935 SHA-1: 5f956263c085fe1668ff406bb48c08b100e09520 SHA-256: db2c0d9b40bc1651677fc30830486da2c82471d589269bf1eccb75eedaeb609c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or are hosted on disposable domains, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings support the presence of external URI links and a link farm strategy. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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.w.radeton.cz/ckfinder/userfiles/files/13418354817.pdf In PDF document text
    • http://esistore.be/userfiles/file/vuxede.pdfIn PDF document text
    • http://kasargod.net/uploads/file/2181730165.pdfIn PDF document text
    • https://erdenet.mn/userfiles/file/51851684532.pdfIn PDF document text
    • https://genimmigration.com/viking1/uploads/files/77420524558.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/98a26931e01ddd3c3403b998f16c5b99/fakevevunonoposibex.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079b37b40042---zogusufubabunabi.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/jokevefolukarugelaniz.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce43143daf---wasebawiwejiniduvuvo.pdfIn PDF document text
    • http://mynigaoe.com/upload/file/20210514194602.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/66332872721.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/goxagim.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16071b4dd2b2b9---21190332861.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160c58db33ba6e---90398359948.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/ruperagobofugolepapisoler.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/2a89b35226bcf2c35161e04ef0de7bf8/dabuwusofebemu.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/b9506f2e574a9e7fc4dcc57190924628/xabak.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/3d246d7f3618bda05b2fc26f80220ae6/55948973478.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/ifg1u8uh0ejrmafg2hkfhoae27/91309113832.pdfIn PDF document text
    • http://fautographie.org/images/userfiles/files/53516783220.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/rb6216fhat8dda1pek0nndcc7h/79610877815.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607050e2eef22---69424767711.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/q1aul2ett2kbbo2si4ovddsd0q/37263564671.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/741bda23203f516b519dbeb65745633a/88504942894.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=libro+de+espa%C3%B1ol+lecturas+sep+cuarto+gradoPDF 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_off0000c14b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC14B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95D 16704 bytes
SHA-256: 790ed9a94075b2c829062771041f064645e6f774e75f848ef55ea3ca97972a4f
font_02_sfnt_off00010382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10382 10988 bytes
SHA-256: 74a7d751c356e5465319a192f2a1525d7990beac81e2cb3af4df3b5d5a13cf4f