Malicious PDF — malware analysis report

Static analysis result for SHA-256 825a66c124b5365a…

MALICIOUS

PDF

77.5 KB Created: 2021-09-20 11:11:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d88af19c6c7255ae69972ad1d20d5c48 SHA-1: 7d02ab21f05637945b66280b7f475bf0936908cb SHA-256: 825a66c124b5365a33492c67dc668d401ee2aa17abc1cff8ce0545fd39caf1b0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs pointing to compromised CMS uploads and disposable hosting, indicative of a link farm used for SEO poisoning or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://irlanc.ru/uplcv?utm_term=clustering+meaning+in+machine+learning PDF link annotation
    • http://bakersfield.thepokeluau.com/uploads/files/3611014891.pdfIn PDF document text
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/xoxonafesugu.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///repodo.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/55962880819.pdfIn PDF document text
    • http://drumlockingclamp.com/FCK_Editor_Images/files/roxidozanilepopowowiziri.pdfIn PDF document text
    • http://mediasingrid.com/js/new/fckeditor/userfiles/file/gufenoworug.pdfIn PDF document text
    • https://chulintemple.org/CKEdit/upload/files/nifavu.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e60e0b6c8a---91196282031.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/a6400a168e734980e1c4ff74598a5c66/zuruvexuzoripisufufaz.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/mc7h63dpu7lcv3ttrfrqah0hfb/xuropilovowunefupi.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/ec62d87c592741b182ff68ce7a7b2d86/7095557837.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/kosuzu.pdfIn PDF document text
    • https://ms01bet.net/contents/files/68902684464.pdfIn PDF document text
    • https://kapokcmassage.com/uploads/files/202109031614333432.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/e9562dd56e91a5ca8f7770640cde8f37/lefezo.pdfIn PDF document text
    • https://transmar.biz/ckfinder/userfiles/files/1954708483.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/zabolevekojagerokigixebuv.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/31084834981.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1631121597.pdfIn PDF document text
    • http://michelschuurmans.nl/images/uploads/file/16102855956.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614670e053454---januxax.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/foxesuxinawi.pdfIn PDF document text
    • 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_off0000cbca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e3dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3DC 17232 bytes
SHA-256: 938ea832f2ec19241d009845b114e437c444b646dd42d5c62c3ccdfa5d973646
font_02_sfnt_off00011079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11079 10688 bytes
SHA-256: eed047ccec89e89d55f84bd6fa37e353755fde018b2d66a25c52e53f51ae2a9c