Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad2884bb26737063…

MALICIOUS

PDF

76.2 KB Created: 2021-09-23 09:33:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a1a10520c15df97ad086382a5da18250 SHA-1: 876f1b2ae04b53390e81deffc10e1d7dd48d7edf SHA-256: ad2884bb26737063db4d00faf739263d707871970b21b10c2a0c2cbceb6e4344
74 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by an ML classifier. It contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm strategy, suggesting the primary goal is to redirect users to potentially harmful sites for phishing or malware downloads. The embedded JavaScript is likely used to facilitate these redirects or further obfuscate the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

Heuristics 5

  • 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://queure.ru/uplcv?utm_term=unique+vpn+apk+download PDF link annotation
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/kejebexanukirib.pdfIn PDF document text
    • https://nusantarabet4d1.com/contents/files/miwibezop.pdfIn PDF document text
    • https://urbanlivin.lu/userfiles/files/13854864290.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/95203005540.pdfIn PDF document text
    • http://saikunghouse.hk/userfiles/midonigob.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/65777881781.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/3071118567.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/jolibomesukiwoxuloja.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/13095639113.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/sanerufogobefobefadi.pdfIn PDF document text
    • http://rspon.pl/images/wyswig_images/file/rapexaxerubolivenewunila.pdfIn PDF document text
    • http://npas.ru/pic/file/foposolukulitepojurizu.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/83876489852.pdfIn PDF document text
    • http://www.hgekc.com/media/userfiles/file/vivofulowolelu.pdfIn PDF document text
    • http://vaonhaphatphap.com/images/uploads/files/noxikoxutokeboje.pdfIn PDF document text
    • http://robvancampen.nl/userfiles/file/lakemedu.pdfIn PDF document text
    • http://incomingmakedonia.com/files/files/vupuni.pdfIn PDF document text
    • http://synowka.pl/galeria/file/befojifakelusupaludajata.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/58012057944.pdfIn PDF document text
    • https://birgatour.mn/js/ckfinder/userfiles/files/kufudinim.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/xitenadivi.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/96217659815.pdfIn PDF document text
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/vogifufemiguno.pdfIn PDF document text
    • https://xn--90aoja6ahg5ds.xn--p1ai/uploads/files/bewimepoxe.pdfIn PDF document text
    • http://union-montage.pl/userfiles/file/76544271129.pdfIn PDF document text
    • http://vevo.keresztessyoptika.hu/elemek/file/52448816753.pdfIn PDF document text
    • http://uchid.com/uploads/file/jezirirefokiponu.pdfIn 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://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_off0000c556.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC556 10516 bytes
SHA-256: 85bb0f720a1e7544136ed06da5aa0d5208c4d76b82d26bcd86a70f664c07d6fa
font_01_sfnt_off0000dd25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF537 17968 bytes
SHA-256: 9ba08f51c86ea28ac0b38dd26b5fc1327f2b5901d3ac3d2d2aa1b955655b9d02