Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c57b88b50b4a191…

MALICIOUS

PDF

72.5 KB Created: 2021-09-26 04:08:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 46e10074133dc817ea215d114ae858c5 SHA-1: 35c8662f68e70830a0560237caf769a94f8e7324 SHA-256: 8c57b88b50b4a191b0e78e806b2aef7047c5b8199ff4619db0544628d5f90933
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or use UTM parameters, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a phishing or malware distribution attempt. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://ketchas.ru/uplcv?utm_term=vehicle+multimedia+entertainment+app+autolink
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161373e814d679---vulutiziz.pdf
    • http://webinaris.net/ckfinder/userfiles/publics/files/27501906418.pdf
    • http://yjbiotech.cn/upload/files/66385469280.pdf
    • http://www.bluewhaleline.com/image/upload/File/40273209147.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/16144aa19392c0---24742334486.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16135c76200a5b---45980096524.pdf
    • http://duz-drustvo.si/uporabnik/file/47488876524.pdf
    • http://mudrkanuch.sk/editor_uploads/system/files/76304929476.pdf
    • http://stellarvvv.ru/ckfinder/userfiles/files/91266102695.pdf
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fbac8e04f7---kufuguferam.pdf
    • https://o2opr.co/userfiles/files/solifovuginonunikifi.pdf
    • http://hingliltd.com/userfiles/gapirodelakimoxigewalava.pdf
    • http://hdurmuslar.com/images_upload/files/3652716402.pdf
    • http://densayhongngoai.com/uploads/userfiles/file/mixanumodopativakewat.pdf
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/kojapakubaxurunod.pdf
    • http://aedelsur.com/contenido/files/vobojitadujesozite.pdf
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/a6d5341666ba9efe6e9e632f8f583b76/zovisudedajiboroz.pdf
    • https://client-sms.com/ckfinder/userfiles/files/23495140925.pdf
    • https://al-farh-iq.com/upload/userfiles/file/rigeziv.pdf
    • http://studiolegalebisantis.it/userfiles/files/69737623340.pdf
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135eefb2da91---31539922394.pdf
    • http://zsdbiopharm.com/upload/files/40096041493.pdf
    • http://ros-audit.com/i/up/file/88318560188.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136483ab8f20---zedone.pdf
    • http://werkkledingverkoop.nl/images/docman/files/linifipofilu.pdf
    • https://itandem.net/ckfinder/userfiles/files/fuzepijevotevuvex.pdf
    • http://paneldeconso.com/userfiles/file/vipuxe.pdf
    • 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_off0000b8bf.bin
60167d87b6b2aa71c58b916357686207118739dca5b3ad46eafe2e8ca6265339
pdf-font-stream PDF embedded font (sfnt) at offset 0xB8BF 10772 bytes
font_01_sfnt_off0000d158.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD158 16792 bytes
font_02_sfnt_off0000e96a.bin
b2a99b98e323a8430ef3a08daf13b88164bfb7ca0b76039f5d46c0c5c5b4bb6c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE96A 16524 bytes