Malicious PDF — malware analysis report

Static analysis result for SHA-256 5aff0a72542b2c83…

MALICIOUS

PDF

89.8 KB Created: 2021-07-25 07:34:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 41859c19797622a64490eee66ee29a7a SHA-1: c54854e54c9df8af956cb91301751a2537a75136 SHA-256: 5aff0a72542b2c8364230dac6c0d59850df9a20cc59ce9ebb938d2768982c6b2
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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://ohcsi.com/ckfinder/userfiles/files/bukulonowosirafuwepokam.pdf In PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/foweg.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/ciq9dhgkqv9j4h6o1af8r6s22s/doruregaz.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c86b5451b2f---suvawulabuxapuno.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a70bc22e33e---63798165305.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ea9c98b5c---19335819946.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a724eab3548---87559232581.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/vtoosd907q7b3q0gt27nte5h0f/jufevedunoxavelinu.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/gepadigofobe.pdfIn PDF document text
    • http://ricoconsultingattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gajovanepa.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5463cb2e8e---1456793852.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9b7d5ff67---6432710259.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/lewove.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5752952fa---zegub.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/dakonozelepogovukav.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2fa102411c---lovogarililodubo.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/wozuxavegowudawolopejegi.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/1248309670.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/59765879869.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/babidiporoxedudobupemol.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/buwekopitivoloxavulona.pdfIn PDF document text
    • http://magnachip.cn/userfiles/file/20210515015929.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608f208998743---22534953559.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/50137139101.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/2da4c05a4b8c58adfd1d8ec2ec0c7c4d/37704312380.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/ff13b61c4e44f35e690d145e9adebd86/dogimaxabazaxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=daily+task+list+template+for+word+free+downloadPDF 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_off0000f9e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E4 10952 bytes
SHA-256: 9189b8a12f8c0ec3cdf4c1ca7f488e0852ebd5f33eca40cc111871f2bece9270
font_01_sfnt_off00011359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11359 17152 bytes
SHA-256: 1dda9d9703bab68a6b313e795063f459a5b5aa62c960d8a51f7d268887450cb8
font_02_sfnt_off00013ffc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1