Malicious PDF — malware analysis report

Static analysis result for SHA-256 521f25c7cd2e9bad…

MALICIOUS

PDF

72.9 KB Created: 2021-06-14 03:22:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 29487c185c5455de42b78a98c54ac9c6 SHA-1: b880b7df6b571fa7b6cf5baa2c34c27e7a19339e SHA-256: 521f25c7cd2e9bad52d9c4ea52bc1751c2812ac06902d0ddbf13c0b7ed8b0656
164 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. The presence of numerous links pointing to compromised WordPress sites and disposable hosting further suggests a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=the+caged+system+demystified+pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a6be41e2f56---nanovegow.pdf
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/41945e92ada2c7ab72e6bc2cd0ecaa24/57291507246.pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a920b9a13---duxaligub.pdf
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/32i9dpdocu16jf0cf7rkhe7as9/keteroliruxiko.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096e22ebc601---namebatujad.pdf
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16090ae40f2e53---45003602667.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a8a7a5f5d---58883697044.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/87551843240.pdf
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/eutvpqd8fhm8il74ah5qita63m/93189988865.pdf
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/pp5oug4jdhs3v06p2pv82pg50r/18769152553.pdf
    • http://carnow.jp/js/upload/files/39926574043.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/tiv06bter3rvjev4k1j3r70ufo/bafibitonovo.pdf
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/0107c8c9185e871a3c510f702e5f1560/10210989090.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/mol84pi38m2c94v5r1d72n4v4f/78545037359.pdf
    • http://mhfmjournal.com/data/22/2/55/64/2544879/user/2788947/htdocs/userfiles/file/23641228760.pdf
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/nj6a5c31b1ffs22ccvb7u541o4/jaripubepuvawusa.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/a2b87041eee34465533ae99c2e253861/21650333818.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df3b.bin
380a15e06224d43582a294c7749a91088fca00af61b892f0c5b36fd9c2a7f9c4
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3B 5492 bytes
font_01_sfnt_off0000f1d6.bin
5638a9ed1f8c4056202c5eb9ebd10dfcbc1aae4620f40d895e9e1c679957235f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D6 11336 bytes