Malicious PDF — malware analysis report

Static analysis result for SHA-256 eef3d25e56adcb74…

MALICIOUS

PDF

89.5 KB Created: 2021-09-09 22:58:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1a3b722684dde290c1692ce392aa4d57 SHA-1: 683fc69de046d7ffbc27b242429b96b645245535 SHA-256: eef3d25e56adcb74e21ad1d6da472e07ae7b86c9a4756137a3364ae0cbe079fd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to other PDF files hosted on various domains, indicating it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is not a legitimate document but rather a mechanism to distribute or obscure malicious content, potentially leading to further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://rayocazar.com/images/elfinder-1.1/files/file/tibedobikunareduzokikawi.pdf In PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/50723409598.pdfIn PDF document text
    • http://jcpingie.be/public/files/kisazoruvumisaguwade.pdfIn PDF document text
    • http://talcmanagement.com/uploaded_files/userfiles/files/17000533715.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/58574569909.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/62969858808.pdfIn PDF document text
    • http://marcus-1.com/FileData/ckfinder/files/20210903_2FC22F753A42D879.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/22886170764.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/22362080457.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/pefudeloraritoror.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/23215456781.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/40126885444.pdfIn PDF document text
    • http://rzn-house.ru/upload/file/21596832887.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/997ad4181f93185f66b858c523915a44/61009777231.pdfIn PDF document text
    • https://manorhair.com/uploads/files/202108312323125788.pdfIn PDF document text
    • http://www.keizerco.nl/userFiles/file/66771828597.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/rekirifaso.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210902080036.pdfIn PDF document text
    • https://prospr.fr/ckfinder/userfiles/files/wedawi.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/vetorireres.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/files/files/mowanodoweritokedejuzati.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613397ca90fd2---1223506655.pdfIn PDF document text
    • http://labotinnghia.com/img/files/13951001935.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/tesawagagodiri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+test+app+on+android+phone+from+android+studioPDF 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_off0000f539.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF539 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D4B 18712 bytes
SHA-256: c7996e3d8cc9064f2ffd32b879dce53a480963dab91c5dad6a3a44e9369bf1e6
font_02_sfnt_off00013e66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E66 10896 bytes
SHA-256: 4e49b9ebb313127100e972445d02ac8c7554b9f7691b3a7b1621da5283e799a2