Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7ef721e94710070…

MALICIOUS

PDF

70.2 KB Created: 2021-09-27 06:50:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 894e92fee28f922a65e473cefae80a11 SHA-1: 0a66d8ce1e570691bda06133e1e1b02aefaa1047 SHA-256: c7ef721e94710070a48241501b41001d31d5a980925daedcc0af4ab5b9722524
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The file also includes numerous links to external websites, many of which are hosted on disposable domains or compromised CMS upload directories, suggesting a phishing or malware distribution attempt. The presence of embedded JavaScript indicates an attempt to exploit vulnerabilities or deliver further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://thienthaopc.com/upload/FCK/file/silefefaf.pdf
    • http://oroblupiscine.it/userfiles/files/bofipovulujurekemujumuzi.pdf
    • http://ex2010.com/uploadfile/file/2021091012301473499.pdf
    • http://smolensk-bakaleya.ru/userfiles/file/6368509812.pdf
    • http://epmachine.ru/d/files/sorutu.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5dbc31f08---9237899426.pdf
    • http://sujitonweb.com/userfiles/files/63904281555.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d012b9dd8d---40053111670.pdf
    • https://pfollowers.com/ci/userfiles/files/bapidimuz.pdf
    • http://thienthaopc.com/upload/FCK/file/xipivubalaruwov.pdf
    • http://terredellamagnagrecia.com/userfiles/files/vefukenekajilapegife.pdf
    • http://caogenzhiben.com/filespath/files/20210926221847.pdf
    • https://sanaspinler.com/calisma2/files/uploads/vanuwep.pdf
    • http://rakkhunnursinghome.com/user_img/files/20503200586.pdf
    • https://usssecuritate.ro/userfiles/file/56687301772.pdf
    • https://goldfieldssanddrags.com.au/ckfinder/userfiles/files/67770605150.pdf
    • http://www.lasallelille.com/admin/ckfinder/userfiles/files/99801832876.pdf
    • https://soportedevida.mx/ckfinder/userfiles/files/8842431423.pdf
    • http://exteractif.fr/pictures/2/84482404022.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/830b0d716cb450c434a93680e4e20e4f/68296884079.pdf
    • http://koreanhotpot.com/uploads/files/mozitepezexosenu.pdf
    • http://alotercuman.com/ckfinder/userfiles/files/sofigidulira.pdf
    • http://due.pt/js/ckfinder/userfiles/files/53433770697.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/budmr08nu89v8sc77uqcnvceu0/vuvulotidolejadof.pdf
    • http://crestviewshopping.abwingsmd.com/uploads/files/finoxazazorasosipawaped.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=how+do+i+make+dark+purple
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b4d0.bin
d4e507148b64b13d2f44b09591feab0b122294bd2e15267b251daf566efab948
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D0 10452 bytes
font_01_sfnt_off0000cc74.bin
f1c2190edd53201ff9a39b61b5b89e264c3f3c418244714e2d92aad09a7af756
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC74 15300 bytes
font_02_sfnt_off0000f31c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF31C 16792 bytes