Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83291d36db3baac…

MALICIOUS

PDF

87.4 KB Created: 2021-06-26 04:15:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6519f0bfea57fc0ca662aba00efa9684 SHA-1: 768c840c7d26b10828d89192ec2167a2cd98fbd9 SHA-256: b83291d36db3baac745cba06b71bcc5d5370f6cf99cb5b75a438fc231a5fad1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of external URIs and link farms on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=were+leprechauns+real
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609eaa309a181---79422047119.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16075e7a29cc0b---robiredefi.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b5905b335a6---jerexawowaxesu.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160930c9239592---90120644860.pdf
    • http://www.elitagida.com.tr/wp-content/plugins/super-forms/uploads/php/files/q9m8j2vps2859ct4vk7munkg01/bumodinogomixo.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16073b7674d4ec---16340014226.pdf
    • https://castel.ro/userfiles/file/78568715998.pdf
    • http://alrabbancapital.com/file/files/werorowuxujasamidodur.pdf
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a14a0c5ac19---kimufuvo.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/1021b2976c77fbbaa3d57016aca2af86/25146093078.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f134805bd7---26050738231.pdf
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/s5oiuf8v7g07h56ok45u00fukj/34730043738.pdf
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/4563d539a0d0a1bf2a72240f008a8012/49505906649.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acaa7d71f97---18739770392.pdf
    • http://yaqeen-eg.com/userfiles/file/58540442170.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5f015b634---xepokat.pdf
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/965701ed697175b3294ee9b078887ec8/75702033283.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608cba793312c---riwigu.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/1a17a92f872cb68518b05ca14f7d4e21/duxeruj.pdf
    • http://pincailight.com/zk/UploadFile/file/2021060500191273499.pdf
    • http://re-view.online/fckFiles/file/574473145.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099f28b84a60---namorukutopuweja.pdf
    • http://diversecityuk.com/userfiles/file/rosuvawowemorilujo.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160837827c7a93---25220497966.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_off0000f498.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF498 16792 bytes
font_01_sfnt_off00010caf.bin
1f1bd46ec8d066fe31e2f70b49bb613a17e1e48317f8178a89ef82b187d64d47
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CAF 10252 bytes
font_02_sfnt_off000123a7.bin
7c8aacb80e91d00c637ba9083d55457e16701395eb975cc70304a360abba3e67
pdf-font-stream PDF embedded font (sfnt) at offset 0x123A7 17500 bytes