Malicious PDF — malware analysis report

Static analysis result for SHA-256 90745879c1807fe1…

MALICIOUS

PDF

160.5 KB Created: 2021-06-10 08:13:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: a83dc123d89cc1ddc7301bf1958496a7 SHA-1: 9fb39341df9179ef9c8cc261dbb5893049f54d08 SHA-256: 90745879c1807fe14510d6dfc90a5b712940da7c1cdc0f523adbf34d51ae2231
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://crysiq.ru/uplcv?utm_term=fce+practice+tests+pdf+2017 PDF link annotation
    • https://transport-vehicules.fr/userfiles/file/xopuxefujizutuzewajuji.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a5df438244---99366608958.pdfIn PDF document text
    • http://www.buildingmalawi.com/images/uploaded/documents/25053017855.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/624ad3e697ea036b43ead4a1f1afe1a9/73423982739.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/0599e1994fbc3528706b2119621a933c/zigubutemesixe.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081b71e8136f---xiselevovap.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b75f229ce1---nenebefevorunesosiviro.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/47e2df3387c28cc88339a0a751f394f9/tixaxefu.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cae25e41e6---59170040631.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7e4255406---71758464245.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1371b2c90---53187882742.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/5c4aee065ff098dedc56f185c9081ffd/mafidikamavov.pdfIn PDF document text
    • https://aashianarealty.com/file/95916163313.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607029010b8b3---1356743239.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/vaweto.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/pisawoliwatujonazigob.pdfIn PDF document text
    • https://antae.be/app/webroot/uploads/file/lokumilugirad.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/bo48p86bc10e3buct5v5roprov/68212100361.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000234fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x234FE 5476 bytes
SHA-256: 52b8a9fbe9032caabc47f0bc32c7ee5eb7f972400440a72bd309278dba7992d1
font_01_sfnt_off000247b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x247B9 13716 bytes
SHA-256: 11eff1e34baf33b62d7f4bf68bf477af1a2cef1fbdf51e81f1aac8cb90a6bb25