Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eb8f9ea156d2de1…

MALICIOUS

PDF

84.5 KB Created: 2021-08-28 11:58:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5bc33b36f20faa7fbd5ae508d0ae37eb SHA-1: 971bec7b384d0ff9daa6f33691740aeb362fdc96 SHA-256: 4eb8f9ea156d2de1fa6c98371f0b4d98c5b953333bd915156a8a27fb4d1509fd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload directories. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to obscure the true malicious destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/dodefusulekokubiwe.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/6cdb84b86f1d59424ef0c53cd32c1563/20682921499.pdf
    • https://olympicwroclaw.pl/zdjecia/fck/file/wurutul.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16073caadc03df---31409971411.pdf
    • https://hashtag.school/userfiles/file/tamaraneguxiger.pdf
    • https://jooli.ru/ckfinder/userfiles/files/42569745995.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc21cac217---domakebu.pdf
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/l4bu4ag4njnav9h0a7ehicam6c/70689001434.pdf
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/mef5qp1tp86emd5io6gouepc1v/natava.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/t36oqemajqk283hif4gil9qlk0/93440922533.pdf
    • http://51-lq.com/userfiles/file///10430733690.pdf
    • http://kovacsoltvaskerites.hu/images/file/dofexeladi.pdf
    • http://mdbim.pl/ubezpiecz/obrazy/file/98616024884.pdf
    • http://mikailang.net/userfiles/file/20210510012538_1213237715.pdf
    • http://thecreditcrisis.net/clients/73966/File/78851818070.pdf
    • http://abwingssuffolk2.com/uploads/files/ziweripuzites.pdf
    • http://canevinclassof70.com/clients/6/6b/6b8b8ee0d314e59372afbcb75100d768/File/segibizekejuwawikob.pdf
    • https://allcreaturesinc.com/files/files/xugotutaredidedukafajo.pdf
    • https://www.barefoothoa.com/webroot/js/ckfinder/userfiles/files/24703692934.pdf
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/77be240a937d8ea27baa4aa732d4aad9/82367034735.pdf
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fa4112ee4fd7bd69031fcf03bcc87024/8677971951.pdf
    • http://szwygs.com/upload/89208499803.pdf
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/e3326adb8c726bf1578661b954c3da09/20215483916.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=a+good+place+to+fish+near+me
    • 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_off0000df8b.bin
b193dbcbda59347b60800b4687797534f687ad91c47714dea42519aba867d963
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8B 20264 bytes
font_01_sfnt_off0001126d.bin
07454992aae670e8358424cf6ab7cad372e63b2ae8fe63dcd864ed2659ae7a3f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1126D 11048 bytes
font_02_sfnt_off00012bc6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC6 16792 bytes