Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7e35b935996df36…

MALICIOUS

PDF

81.3 KB Created: 2021-09-16 20:53:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 456e954bba8106b512f4d8ebc562756a SHA-1: 99bb3cfc522a506183c25a22536eb60a01f5239f SHA-256: b7e35b935996df36ccbc24eb96fcdc25e35555b613349bfda1f9bc6bffea975e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is a link farm, and numerous external URLs are present, suggesting an attempt to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://zvaracskaskola.eu/editor_uploads/system/files/tosuwerivofumumosokez.pdf In PDF document text
    • https://dlt-nkp.com/fileupload/file/67986178823.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/fiveruletuvelaferofut.pdfIn PDF document text
    • https://coherence.cz/userfiles/file/44863146933.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/xawanitup.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/3d62efceb4368ba5b87d125958af8203/7434248641.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/25831012751.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/jaridedov.pdfIn PDF document text
    • http://orthopediedelft.eu/files/rimibilu.pdfIn PDF document text
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/51295820790.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/96869995056.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/23723126951.pdfIn PDF document text
    • https://shidoremicrosys.com/media/38799373374.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/sitokevadanimifapunemoxus.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/gikosafedafumi.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/38578897106.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/lasododorazaku.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/33941357168.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/26021495994.pdfIn PDF document text
    • http://aucontecnologia.com/userfiles/files/kuvodov.pdfIn PDF document text
    • http://irfanmakina.com/depo/sayfaresim/file/ponafatuwaxebitedum.pdfIn PDF document text
    • https://war-old.its.vn/new/userfiles/file/38921184630.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109160019576689.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/dolowozupofa.pdfIn PDF document text
    • http://irths.com/upload_files/files/kelinijefamasumes.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109021736162551.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=set+parental+controls+on+androidPDF 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://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_off0000d924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD924 17668 bytes
SHA-256: e09caa65509533d6fadf3914591e2af21c47b02385fd37b4399324e27509f26d
font_01_sfnt_off000106c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C4 10580 bytes
SHA-256: 83137237b7864d312e6348f2c0900158404646293de2455a67b51019c5a9c5f7
font_02_sfnt_off00011ef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1