Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d23915b15b68357…

MALICIOUS

PDF

72.3 KB Created: 2021-06-06 01:46:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 9c253195281ca39866576c61c6dcda4a SHA-1: 20673b36c6290124490be0587f14df707649e8ac SHA-256: 3d23915b15b6835772cc915a4cda75ab83e08ae4a9080efe205095c1b277c1d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and other disposable hosting domains. The embedded URLs, such as 'https://coretry.ru/uplcv?utm_term=how+do+you+measure+ear+gauges', likely serve to redirect users to phishing pages or download further malware. No scripts were extracted, but the overall structure suggests a phishing or SEO manipulation campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://coretry.ru/uplcv?utm_term=how+do+you+measure+ear+gauges PDF link annotation
    • http://amoy-art.com/Upload/file/62072910002.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/b82f6e919e6280442a7c81c15b2eedb8/borefax.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4ab64efb8---xadirivu.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/4d2d55badf988d9e25815256e134c501/77099489334.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/50131974223.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/a668ml2u9i7qrd42618clsbj4c/kebijebesul.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/turovelu.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/ranexulaj.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/l9a5l66enimhcuasvdf04gee90/53475191375.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160748cfaab377---webisap.pdfIn PDF document text
    • http://gphs84.com/clients/866382/File/zegurimim.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/cb2f238927ff89a6f030c734166a3305/teneni.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/ea297a13ec05642ec87262c8e3e4c697/89431473021.pdfIn PDF document text
    • http://praguetransfer.com/files/file/pijek.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a0744203894---joraxoravijirunole.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/as0dmbqem87d4oha82nqf49p8k/dizanonujefokuxewibapol.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160784a7be0c61---54029664291.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_off0000de42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE42 5268 bytes
SHA-256: c76df488f6e830acbd3a74517ebfb33e8cb71d34a174869997c85cf8585c7dd3
font_01_sfnt_off0000f02b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02B 10612 bytes
SHA-256: 0f72d2df63d10a0f11da5e61f38aa0766f0c5883278142e3e45c3f24d2e75bed