Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55df24938ad382e…

MALICIOUS

PDF

102.4 KB Created: 2021-06-30 07:17:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f6f8cdf1fc2d68e2c33545f18358663 SHA-1: 61adb81538ef90d29ca2579d4d9ff6471cd731ae SHA-256: c55df24938ad382ee6d823083de0d2b90925474a7e1220fc8e013f497ac206c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160973147af674---77091435256.pdf
    • http://3bbb.fr/ckeditor/upload/files/11787929115.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/5115c57e10cda8e085271e344aaf77bd/gofasizivowomupodagijaj.pdf
    • http://extrastyle.ee/ckfinder/userfiles/files/dunigiwix.pdf
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/0ba6612b6b15900fc3a4fc362e61be59/19889729235.pdf
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c0e3230c53---93730370627.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ppsh65aab82mg7di9nqkl6d2fq/bopasigilobo.pdf
    • http://berallebags.com/UploadFiles/FCKeditor/20210613143304.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160952a7f3c235---patojasijekoxoxikajokila.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccff1da815---jebeno.pdf
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/b7fe637b6af0fd8b56ec483c386a8353/87417169105.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090ce1f0ad40---6426837592.pdf
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/3ff27ccc752c14fa2bccbeeb5be19a69/70845414713.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb263da105---15602874914.pdf
    • http://tuhs1970.com/clients/a/ac/acc339db084e87cdfae31a76a6c96f1c/File/95765811048.pdf
    • https://houstoncoinshow.org/FCKeditor/file/fipudujakagu.pdf
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nosepuxuloxupataruvijaroz.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbbc379738---zemufobagupu.pdf
    • http://thrifty-uy.com/files/others/30202262086.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/1oncr9at4bh5apkn4cr4nrsev4/mosidoziwewonavu.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/160876d25ef73b---tuwogaboravos.pdf
    • https://amd-export.com/site/upload/file/japemalewifiridonowepawe.pdf
    • https://pt2-turbo-j3t.com/contents//files/20277745796.pdf
    • https://mayurherbal.com/userfiles/file/12592815146.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=movies+alicia+keys+played+in
    • 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_off00012d33.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D33 16792 bytes
font_01_sfnt_off0001454a.bin
a2b48adc5dce9742b595a77ef19197b9e1f59e5d18ecde3088a6b45e8ae6f099
pdf-font-stream PDF embedded font (sfnt) at offset 0x1454A 10576 bytes
font_02_sfnt_off00015d98.bin
bb15ac4fa0f877333db7be67b15302f764c63309e24a13a9a887389cffa492a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x15D98 17732 bytes