Malicious PDF — malware analysis report

Static analysis result for SHA-256 3544e8b8d4266bfc…

MALICIOUS

PDF

71.2 KB Created: 2021-09-28 09:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5186cf2c23c46dfa75c0c54dfbda1f31 SHA-1: 9bea31a9dd971f6a78a865c00517ba506a46d042 SHA-256: 3544e8b8d4266bfcfe9aa90a5c7111289cb37efe8cb893b2a0e136539e118a81
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to suspicious domains and are structured as a link farm, suggesting an attempt to redirect users to malicious sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination. No scripts were extracted, but the overall structure and URL distribution strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://jyotiacademicpress.org/uploads/file/gebabugurokasajow.pdf In PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/warug.pdfIn PDF document text
    • http://theleadershipworks.com/PO2/UPFILE/userfiles/files/60950087549.pdfIn PDF document text
    • https://pepinieramontana.ro/ckfinder/userfiles/files/86626519403.pdfIn PDF document text
    • http://jiji.pgo.tw/pic/uploads/files/1642129268.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/zajitidomajumotubus.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/numawimijalokadepozo.pdfIn PDF document text
    • https://bloc-immo.com/images/fuxetetelitopogeme.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/jefitowaduvasi.pdfIn PDF document text
    • https://otomatcilarmetal.com/otomat/upload/files/balotufujaxeregejosu.pdfIn PDF document text
    • https://wrd13.com/force/file/gavinovitebixego.pdfIn PDF document text
    • http://nomorecpapmachine.com/userfiles/files/73822253267.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/91942957574.pdfIn PDF document text
    • https://semangkamerah.com/contents/files/62305451550.pdfIn PDF document text
    • https://xn--80apefbdm9ah5g.xn--p1ai/userfiles/miratedofivefamik.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161411118f310f---23951994208.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/xibijafefukekukurazu.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/jekuzavewenefolalopavox.pdfIn PDF document text
    • https://familienbilstrup.dk/userfiles/file/rexesepaxewuvudodo.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/budolatumufadupevol.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/2975175838.pdfIn PDF document text
    • http://eprdel.cz/userfiles/file/54935540633.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/tipuxowudodowerimepu.pdfIn PDF document text
    • http://icareonline.net.au/ckfinder/icare/files/19353641857.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/gafojurisaveg.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/rebeta.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=auto+clicker+super+fast+pro+apkPDF 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_off0000b361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB361 10544 bytes
SHA-256: 7a3a7958002929943a6e8a0990f1be0b33756a75160f1aded33a1457b10c24ca
font_01_sfnt_off0000cba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B6 16472 bytes
SHA-256: c08976e9f988b1f1b450f4d2bda9f1e3205fe5a32c0238871468306af932f84e