Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f9b45164cda8e8…

MALICIOUS

PDF

70.7 KB Created: 2021-09-30 19:18:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 049fda8d7ebd2f264e133344d5d1f2bf SHA-1: 4700b39c7066d1d4f442eff9e9bb461d43dbc00d SHA-256: a4f9b45164cda8e8b0b51cf726e6baf90369bbe8c64f18a523bcf2664aec17f9
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a large number of links pointing to disposable domains, suggesting an attempt to obscure the final malicious destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a second-stage payload via the embedded JavaScript and the numerous URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://kopdesign.nl/userfiles/file/lazoxuzi.pdf In PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/67223828375.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/viwumijafuvesinosodin.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/towaxufigukubapar.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/161448bc514d66---90016535934.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/92413808301.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/62497556800.pdfIn PDF document text
    • http://ktcyy.com/ckfinder/userfiles/files/3133466335.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/64790446925.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/xiruz.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/gupabixi.pdfIn PDF document text
    • https://fulzugaskozpont.hu/files/30026170453.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/dibuvijolinitevavar.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/82094118825.pdfIn PDF document text
    • http://waterlootour.com/FileData/ckfinder/files/20210916_75F785782D11F39A.pdfIn PDF document text
    • http://mama.plovdivweek.com/js/ckfinder/userfiles/files/2074733752.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/gogipokifivuwoguxok.pdfIn PDF document text
    • https://italvaping.com/file/siwifusogiwo.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/fudujomebolasibetinukidef.pdfIn PDF document text
    • http://ardennes.proximeo.com/ckfinder/userfiles/files/xazuverimuguxodakad.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/sodoligulajof.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/7454230101.pdfIn PDF document text
    • https://laughteronlineuniversity.com/images/upload/files/34006619436.pdfIn PDF document text
    • http://chargooshads.com/images/upload/files/77530617659.pdfIn PDF document text
    • https://groupekineconcept.com/userfiles/file/52794377705.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=lucky+luke+comics+free+download+pdfPDF 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_off0000b0e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0E5 16468 bytes
SHA-256: 206cbfe3ffc6e2b484b0bec8b71f54797dcea80c111e85082b59991ec92549f7
font_01_sfnt_off0000dafa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f311.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF311 11032 bytes
SHA-256: b286995b5b4587888c7fb542f21dd550c365c6c0573a851e9c94e1f654d9b41b