Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3d4dc78a813519…

MALICIOUS

PDF

87.8 KB Created: 2021-09-12 22:32:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 081ce7539239487fe9d3d138ff2d994a SHA-1: 0f9fd3f160c33a9c28f1fa1afc613c21b97d1482 SHA-256: 8b3d4dc78a8135197e732206b22fd75a82d0f63643d623523afbf1adcd4597a2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://wangyiphk.com/userfiles/99984242191.pdf
    • https://madeinstlucia.com/userfiles/files/5883575606.pdf
    • http://okwmd.com/upload/fckeditor/file/65553309597.pdf
    • https://franchiseharbor.com/files/files/robepegogedafag.pdf
    • http://alfonsoguiggiarchitetto.it/userfiles/files/fudavajamususabatip.pdf
    • https://anjingliar2.com/contents/files/5353121892.pdf
    • https://cvssteelex.com/ckfinder/userfiles/files/7939746202.pdf
    • http://ornito-silesia.eu/userfiles/file/tozes.pdf
    • https://www.prshots.com/ckfinder/userfiles/files/83190236906.pdf
    • http://miyozenemeryville.com/uploads/files/rezisanenubo.pdf
    • http://solamsys.com/userData/board/file/foxozir.pdf
    • https://solucionaesp.com/ckfinder/userfiles/files/62450583319.pdf
    • https://sukienmiennam.com/userupload/files/wowede.pdf
    • https://seedcambodia.org/htdocs/cljr/data/files/5934837205.pdf
    • http://musclecar-taps.com/js/upload/files/nevoxirimala.pdf
    • http://hongphuc.vn/userfiles/file/fixenodatudugotujaxuxa.pdf
    • https://nothingbutsafetyglasses.com/userfiles/file/zavasujomaworiv.pdf
    • https://expobar.vn/app/webroot/files/images/pages/files/bopexuxopibulimewelirasub.pdf
    • http://czpohledavky.cz/userfiles/files/nusujulimusuzo.pdf
    • https://huanghecables.com/d/files/29012189419.pdf
    • https://penzionradvanice.cz/res/file/57141802058.pdf
    • http://myphamhelios.vn/luutru/files/61633688502.pdf
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fupaxipomutixegajab.pdf
    • https://huanghecables.com/d/files/jozukigodubonugefexozuze.pdf
    • https://abicecream.ru/ckfinder/userfiles/files/84351024893.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=best+marvel+wallpapers+for+android
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee32.bin
aad0e447e5611000dcd3272ff2149dd3c2908f470f58e3741d4553aee7e9b39b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE32 18932 bytes
font_01_sfnt_off00011f48.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F48 16792 bytes
font_02_sfnt_off0001375f.bin
24d4e9adae76b4ad4608e9e502fb5721f0eaa9179f4ea760ba3243a0d286f5de
pdf-font-stream PDF embedded font (sfnt) at offset 0x1375F 10864 bytes