Malicious PDF — malware analysis report

Static analysis result for SHA-256 90a5b270e0e14959…

MALICIOUS

PDF

75.0 KB Created: 2021-06-17 10:52:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 2ce073eb92dbba4ee3aba884057bda3b SHA-1: 9bd408a15937dfc70f4594bd96407afe9b82e83f SHA-256: 90a5b270e0e14959a3905254736eae08a614352330ada8d9c36a1ff45621402f
156 Risk Score

Malware Insights

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

The sample is a PDF document that contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body text is heavily obfuscated and unreadable, but the presence of embedded URLs and the heuristic firings point to a link farm used to redirect users to malicious content.

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://huntic.ru/uplcv?utm_term=free+letter+c+printables PDF link annotation
    • http://zkojicin.cz/userfiles/file/toninuvumogibepukimevix.pdfIn PDF document text
    • https://fuchscars.com/wp-content/plugins/super-forms/uploads/php/files/a998dbb61fbf6e7bdd0c54fe327ac697/15893285436.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/0edddc85070eafaad00a2e8fed5ae425/podutefejexige.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/wepirorekitamaxom.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/luxurogoterijupo.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/4fc087db13f6c8eccb22e5703fbc3f07/62693886285.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160753ec9670f6---98012629083.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1609d583abf7c0---55008978471.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/04a072564245979902b1051c1cee5721/89059981199.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/42057904517.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/1e11ceffabda168ab4ce164562af199a/10065253869.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa78f3b93f---3578693829.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3d31f4082---savetobonuluwasit.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/sofifinowefaduzokovazidab.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_off0000e950.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE950 5020 bytes
SHA-256: c61ce516804a48d7a0be51749028bd64cf537a395b05fdf3cf74c1fe28d25526
font_01_sfnt_off0000fa6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6C 11064 bytes
SHA-256: 174d0b413bd8f4cc5c3e1e15b726695b16cb37524d4e97e324c0402bf74a1fb3