Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9459c45514ecd83…

MALICIOUS

PDF

70.8 KB Created: 2021-10-02 21:46:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c17e7eb90d43f99c61b4bb84fb914ffd SHA-1: 2944ba5a2b30ffcd4094eb8956cacc985558f50a SHA-256: b9459c45514ecd839f5a90b5ad9415395d15702cf229b4daa3b0de5ded54b11d
74 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The ML classifier strongly indicated maliciousness. The document also contains numerous external URIs, many hosted on disposable domains, suggesting a link farm or redirection scheme to deliver a secondary payload or phish for credentials. The presence of embedded JavaScript points to T1059.007, and the overall nature of the document suggests it was delivered as a spearphishing attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 http://ktcyy.com/ckfinder/userfiles/files/85962119036.pdf In PDF document text
    • https://rugsinc.in/UserFiles/files/51872557936.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1633028564.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/nudoradudojive.pdfIn PDF document text
    • http://kiuanai.com/userfiles/file/pavutet.pdfIn PDF document text
    • https://amthanhanhsangchinhhang.vn/upload/files/60164413672.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/57184218903.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/49562689994.pdfIn PDF document text
    • http://kwiatmetal.pl/userfiles/file/44693793598.pdfIn PDF document text
    • https://eltechma.com/zdjecia/fck/file/21101937403.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135979b030f1---65529379602.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/92301891278.pdfIn PDF document text
    • https://rh4-h1tapi-turbo.com/contents/files/zovogefes.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/16195699432.pdfIn PDF document text
    • https://eravukappalpalli.com/userfiles/file/gekowulowifoz.pdfIn PDF document text
    • https://heyratacademy.ir/file/82095017887.pdfIn PDF document text
    • http://sasmedm.com/www/js/ckfinder/userfiles/files/lidukojar.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/33769505799.pdfIn PDF document text
    • http://runo34.ru/attachments/file/galunesedagojaxarum.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/jibopajewadimogodife.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/26101081858.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/9012057611.pdfIn PDF document text
    • http://harlit.com/upfiles/file/xenaxesisakofuriz.pdfIn PDF document text
    • http://sreema.org/FCKeditor/file/42715160094.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/62255303903.pdfIn PDF document text
    • http://www.childofafrica.org/media/userfiles/file/fupozubinez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=need+for+speed+most+wanted+2005+free+download+full+versionPDF 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_off0000b470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB470 11264 bytes
SHA-256: 8229c77e2d121fc17e3d1a73914f647631802cea608125f2bb4b0cb1944faffb
font_01_sfnt_off0000cf06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF06 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e718.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE718 14932 bytes
SHA-256: 8948596093514e631853b59190abcdafdd182c7d41350394dbd788481dbb8521