Malicious PDF — malware analysis report

Static analysis result for SHA-256 8311f4f190ac4f8b…

MALICIOUS

PDF

80.9 KB Created: 2021-06-11 14:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 08784fe4852c8c9c8cbe36e4fa884925 SHA-1: 4651cf19c779dd5251475ad52a1148738991a663 SHA-256: 8311f4f190ac4f8b35cbfa96f3288bc219f24dbba25fb653ead9b2035a74598d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links pointing to compromised websites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and compromised CMS upload links reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=possessive+pronouns+exercises+for+kids PDF link annotation
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0bf1be87b---lebujo.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7fcd0a3e8---zojire.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097d1d94ebd4---1221510128.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b612a2cc3ab.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/81sk552s84l9m9it8pud1l11o2/bisukoniragusepit.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/b837325bbc2fc268ec86054d264d7e30/35849897895.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609408267e649---lukakaruvadunamudimul.pdfIn PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/1fb5f5297e86a9c2cfd7f9689707f98a/megefoxebazunasesinigo.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/46171701696.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088eecc1cfd1---63274278419.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b6eae7c6fa9---kisajizib.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/rsvfhad55gojvjiacgsh89d3u1/40089845765.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083fb38a0c68---82304017635.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/xoses.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
    • 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_off0000ead0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 5100 bytes
SHA-256: cf6adba5877aa5ebb400df904f0e21a768a5b5879f11aa85889b1ea9f3ed3d5e
font_01_sfnt_off0000fc4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4F 10844 bytes
SHA-256: a31097a2de9c5548abc559a79e155d414ef301e429b9f0c16ceaf9720f9a14e0
font_02_sfnt_off00012165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12165 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd