Malicious PDF — malware analysis report

Static analysis result for SHA-256 b95ca61f668828af…

MALICIOUS

PDF

85.3 KB Created: 2021-07-28 08:31:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 220d281d4c2c5582b36b27ad583a0d3c SHA-1: 54f94b948a194dc7f64c0255f62046d7afe921ca SHA-256: b95ca61f668828afff2b6394e0fa7b3f0193e6ad5c50476b05f67a3b20267896
204 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external links, some hosted on compromised CMS uploads, suggesting it's designed to lure users into downloading further malicious content or installing unwanted software. The 'Browser extension / update installation lure' heuristic strongly indicates a social engineering tactic to compromise the user. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/8dq9slfhurp5ko06khrojl8gi6/19061512174.pdf
    • http://salwex.hu/file/29281677160.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/a48a645003a953fd09a67be226fd0664/kewukebemekuso.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607d166090396---20774244725.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160aa071d60813---54692803475.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d57eabc2e59---melofevonixi.pdf
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/38067660486.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/4577b4aaa51c7c71ed4ee47b4281fe6d/36718058867.pdf
    • http://solmoda.it/userfiles/files/mopatapevefusefu.pdf
    • http://xn--e1aaafipco3bk8gra3b.xn--p1ai/upload_picture/file/rupid.pdf
    • https://www.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079fe6ddc3f2---kifajajazuwolagifiwariwi.pdf
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/11664183272.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-6-24/20210624233517660853.pdf
    • https://www.colline-eternelle.com/ckfinder/userfiles/files/fopepejozejenijalokodivaw.pdf
    • https://xn--nmqu14inmf.com/upload/files/10186122827.pdf
    • http://alimentosldm.com/userfiles/file/pufowema.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bc754048112---viperadewasiragus.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a13fe12e5---50908568898.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4bc2a5b4a0---1128708128.pdf
    • https://masihpt2.com/contents//files/9584267078.pdf
    • http://slphs66.com/clients/e/e6/e62fa13cff665df70d7481f632b33819/File/xopav.pdf
    • http://lexus-custom.com/js/upload/files/54458205094.pdf
    • http://one9five.com/userfiles/files/73783184470.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=starfall+learn+to+read+with+phonics+free+download
    • 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_off0000eb18.bin
49281c910511f058acaa3269fd22e9a6c8591b22f72b6dfe6ddca3180ba94670
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB18 10880 bytes
font_01_sfnt_off0001042a.bin
751785eced150eb1c660359e8e3246994d57f739dbd1748478f3382da590ee97
pdf-font-stream PDF embedded font (sfnt) at offset 0x1042A 17008 bytes
font_02_sfnt_off00012fe6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FE6 16792 bytes