Malicious PDF — malware analysis report

Static analysis result for SHA-256 449db1e6e6b89cea…

MALICIOUS

PDF

71.3 KB Created: 2021-09-17 15:50:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f5cf8288ba2e72c3343bc613667f7fd5 SHA-1: 75a03ea5ff037a2d6e6afdabfe410eebff295cff SHA-256: 449db1e6e6b89cea8d0b4f16f3fd2dfb30aa0acc4fcd28935e6c390caa376807
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded links to other PDF files, many of which are hosted on disposable domains, suggesting a link farm designed to obscure malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the presence of numerous unknown URLs strongly indicate a phishing or malware distribution attempt. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 5

  • 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.
  • 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://hmed.vn/upload/files/77327461901.pdf
    • http://aelma.com/sites/default/userfiles/file/zafovututugasutufexakuxax.pdf
    • http://ivankrivanek.com/userfiles/file/zikutojotinena.pdf
    • http://domusanna.it/userfiles/files/49263150493.pdf
    • http://maquinandoysubastando.com/dleyes/admin/fotos/file/9929737243.pdf
    • https://bakwanudang.com/contents/files/52742620713.pdf
    • http://londonjip.com/userData/board/file/fokogukutebirewi.pdf
    • https://rintrans.com/files/pojowekagewojepugel.pdf
    • http://rexant.by/upload/editor/files/93008389616.pdf
    • https://happen.webasl.com/userfiles/file/12901725726.pdf
    • http://www.vandiestbrandstoffen.be/uploads/files/mupoxavokulelamixegalawup.pdf
    • http://nemdanangpho.com/uploads/2021-09-02/images/files/8515946695.pdf
    • https://plewmal-d.com/Uploads/files/kewesatuloxumigojuzujok.pdf
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/munexagegufof.pdf
    • http://traktorpulling.de/ablage/userfiles/files/ruliduvutubivon.pdf
    • http://rockhousemethod.com/ckfinder/userfiles/files/18762268104.pdf
    • http://berbun.com/user_img/file/85458552001.pdf
    • http://membranekeyboard.pl/_data/file/2340730341.pdf
    • http://www.morrisjones.co.uk/EditorImages/file/7751722858.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/uhm3lqvpcadvev8800it2sp4p7/rikafefara.pdf
    • http://montesantangelo.it/files/files/viforimebo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=download+film+maker+apk
    • 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_off0000b772.bin
90b6e0fd793add3217ccafec3b9746f821b89f4525a71010bebca2b118577d95
pdf-font-stream PDF embedded font (sfnt) at offset 0xB772 10572 bytes
font_01_sfnt_off0000cf7e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF7E 16792 bytes
font_02_sfnt_off0000e790.bin
081b35e85de28c0c50f5feff051bcd23bebc885b660d988a5e3cb0342568c952
pdf-font-stream PDF embedded font (sfnt) at offset 0xE790 15780 bytes