Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c3d24bb23fb9a8…

MALICIOUS

PDF

76.9 KB Created: 2021-09-10 09:12:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9e8af68e30930deac2fa7ec58d14f8ee SHA-1: c9dafcc532c9ca667bbc24d44c16edfd72d217bc SHA-256: 91c3d24bb23fb9a8f097b268ae8aca5d2cd80720cd130573938774b5a2ff1ecb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous links to external PDF files hosted on various domains. The presence of 'utm_term_redirector=True' and the sheer number of distinct domains suggest a coordinated effort to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://goodtraefarm.com/ckupload/files/38767037065.pdf In PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/marugujixidim.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/98520000214.pdfIn PDF document text
    • http://makesomenoise.hu/upload/file/88680245940.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/53599424128.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132cfc586b38---23559396737.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/80285427448.pdfIn PDF document text
    • https://terminarz.online/kosmetyczka/krakow/files/66604255608.pdfIn PDF document text
    • https://sanidom.pl/img/file/farinavusadux.pdfIn PDF document text
    • https://totounited.com/contents/files/wivafelapa.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/27174741293.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/tokufanusa.pdfIn PDF document text
    • https://servicepapik.ro/files/popawon.pdfIn PDF document text
    • http://sacmacbook.net/userfiles/file/15121874824.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/bekuril.pdfIn PDF document text
    • http://vouchertiket.com/airplane/ckeditor/uploads/files/42581660341.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/9181213793.pdfIn PDF document text
    • http://goodlack.cz/userfiles/file/vagexukakabafirivona.pdfIn PDF document text
    • https://stiglic.sk/userfiles/file/gexuluke.pdfIn PDF document text
    • http://camara.acessoainformacao.org/uploads/ckfinder/files/zawisovujojukusuriloxog.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/085095d047a3d46ccc3b01c7f4532c93/10150177414.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210903_201252.pdfIn PDF document text
    • https://lrsinc.co/userfiles/file/97229949398.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=vaaste+song+download+mp4+audioPDF 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_off0000c6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dedf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDF 17744 bytes
SHA-256: 64dcb871594007dcb900d2bca393bffcd16e23cbf9a295b6dde7afe3f3c366cd
font_02_sfnt_off00010ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA1 10868 bytes
SHA-256: 3b5e30ddb87589a3eb37323a9aa7005579168049d7f23850de59f9ed10ea8747