Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b55e04aa75be629…

MALICIOUS

PDF

73.1 KB Created: 2021-09-11 13:29:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: fd2e5bb4a0293d454691e7391fe4eba3 SHA-1: 18be6f7e07f10a210ab8f1d57fb4a1761333b9f5 SHA-256: 5b55e04aa75be62909930f6be58abee123ad252ea95ef7065ca643995f221d20
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://nomylo.ru/uplcv?utm_term=resident+evil+3+nemesis+ps1+download PDF link annotation
    • http://tongchangkj.com/uploadfile/file///2021090506031218.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///87959676550.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/vmbuuqg9mtpduhvmopalscccck/69404251908.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/796f6e931408565b94ed2360f3b8226d/vafelojutavumoma.pdfIn PDF document text
    • https://happycolaborativo.com/uploads/files/4310794511.pdfIn PDF document text
    • http://1544-7419.net/upload/fckeditor/file/lurujibowowaz.pdfIn PDF document text
    • http://gibisch.biz/files/files/janemafemevopobipu.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/26427859984.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/mikokexajimivavafoba.pdfIn PDF document text
    • http://motoren-adachi.com/js/upload/files/68760989691.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/zanixojojenininuwosolo.pdfIn PDF document text
    • http://aven.su/userfiles/file/22964708809.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/54691010176.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/68559131293.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/2789648502.pdfIn PDF document text
    • http://influences-vegetales.eu/assets/Image/files/muzejanavupuregikus.pdfIn PDF document text
    • https://stpatswatertown.org/ckfinder/userfiles/files/bejulurire.pdfIn PDF document text
    • http://mawaevents.com/uploads/file/18779724724.pdfIn PDF document text
    • http://e-junghan.com/userData/board/file/lipotobemu.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/92081342324.pdfIn PDF document text
    • http://www.artefuoricentro.it/js/lib/ckfinder/userfiles/files/zalezenavuwuvegomarig.pdfIn PDF document text
    • http://retailcop.ca/files/13235003293.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/16056287475.pdfIn PDF document text
    • https://harom.ro/files/file/ralilizutonir.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/dumatiminizogozotetosod.pdfIn PDF document text
    • 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_off0000bb13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB13 16408 bytes
SHA-256: 4350d516f99e5121af3830df5f6c060a708c54d1d31d630ee65f29435638590a
font_01_sfnt_off0000e4df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4DF 10876 bytes
SHA-256: baf9c59e60169493f96084ca65ae510ce14ea68df2bb9cdd9fef89deb6bce1f2
font_02_sfnt_off0000fe1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1