Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5c4634b66bbe5bd…

MALICIOUS

PDF

86.7 KB Created: 2021-07-02 23:55:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: a33256f68853575a796443c580c3c683 SHA-1: 364f9783c5775a73ef27b1e7b17c735e8b63ad8b SHA-256: c5c4634b66bbe5bd8bc90b7fea2608c7247c20a4723e9c0a481313f344a5d93b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by an ML classifier as malicious. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised WordPress upload directories and disposable hosting. These links likely serve to redirect users to malicious content or phishing pages, a common tactic for SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7f47a2ba3---jemorowosufugulozusabaxo.pdf In PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/de8ae4c7e33cf1ec09e103c303636dd3/lidusopena.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160781d3d9fc19---rixusib.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/a9d113ff0d254dbd04031c5cce287970/16129146496.pdfIn PDF document text
    • http://kezmosas.hu/files/file/nudenazigoxilamebibenasep.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/xonejajizufividovaxiw.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/04f070e58873cef5dc5c0e9808866c69/34053667265.pdfIn PDF document text
    • https://easybuildapp.com/files/uploaded/files/35082200438.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/29cf68176bca6252e74aa48d00f04e49/zafuzurama.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/7af03b5a6a21ab4d74b93cefafefb94e/78788940357.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c81e4b871---76698988927.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/88b3fd64b3ba2cf29c8dbac8421844af/buvonebibedibo.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/4f9c21a81c61ed3ca6dd31652bac7c13/viraxokituxegod.pdfIn PDF document text
    • http://vejwun.cz/images/xikazojakuzowimanet.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b37f78b92f---34627846328.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/d81c887a7651b508f7828e504c1c578e/57493290295.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160da82e54cacd---82758417759.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb9db0ca41---57888034133.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/99799488827.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070507da67ed---71321551835.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/gamaligexumebazul.pdfIn PDF document text
    • https://pindimana.in/uploads/file/xusajasetujipuferusoxesi.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/87889390461.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/77426001890.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c58a9d01415---majalekizaraxudezupadi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=young+jessica+chastainPDF 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_off0000e2c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C6 26164 bytes
SHA-256: 16044fcd05c74f808c12cab4133a63e491ccb929793219f66aca02cb1e9a0049
font_01_sfnt_off00011be4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000133fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133FB 10576 bytes
SHA-256: ebde8a79cadaa6643f5b738f173087e40570f15d38ee72524d1f3d4fdc4739b1