Malicious PDF — malware analysis report

Static analysis result for SHA-256 c13a87f04f9738be…

MALICIOUS

PDF

74.2 KB Created: 2021-05-27 13:36:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 961dc121ea469f2fca75c808d837af11 SHA-1: 420e71441f4cbab70e77df1c800b353a3032cd0b SHA-256: c13a87f04f9738be4a136c7208b55cd0f309159fd03b2ebfeac3da4c01deeb18
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories, indicating a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to distribute second-stage payloads.

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 http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1607d391f35281---22719427669.pdf In PDF document text
    • http://musorcentrum.hu/files/article/file/23338474546.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a548958c0db---sevuwegagapebekewuna.pdfIn PDF document text
    • https://aashianarealty.com/file/93805204065.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/jakugipisudusupib.pdfIn PDF document text
    • http://penzionriverside.cz/files/file/dututagipejamobod.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160727f0e219e8---289557549.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160782953249c8---55508203533.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/0dd464545486aef02aa2deb72c9e91fc/damoboromubijibeneremed.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16093d0712702a---gobutoxe.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/g8iukdm5la76ltkk2904dkootu/nifega.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160722aaa9d73b---luseka.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/c254743038ee04159c7dcfd1e2e7203f/1911901636.pdfIn PDF document text
    • https://webfox.net.au/wp-content/plugins/super-forms/uploads/php/files/3a687dcc8202e38a035c12e5daf9ae83/86542093236.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088f32355d4d---38273206800.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2791581fa---35099235967.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+unlock+nintendo+switch+parental+controlsPDF link annotation
    • 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_off0000e586.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE586 5280 bytes
SHA-256: 265b924780d846b51ef6272ea5c35fceb35133053e8ebb2f85a06689fb4d29d3
font_01_sfnt_off0000f785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF785 10448 bytes
SHA-256: bc538c16faf0fafba1d1245dedeb830338542a3f153607980ec9b986f80c9bf2