Malicious PDF — malware analysis report

Static analysis result for SHA-256 4664f86a9fee07d4…

MALICIOUS

PDF

104.2 KB Created: 2021-07-07 07:18:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 031332e59580977a660f3fd637afb991 SHA-1: e09296587d6377b31fde1ab4ef2514befecf826c SHA-256: 4664f86a9fee07d4774e2e5f23a111b89855ffe5166a993e528f3add6363a536
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous external links, many pointing to compromised websites or disposable domains, 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. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9790

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://pistant.ru/uplcv?utm_term=khz+to+nm PDF link annotation
    • https://arch.ua/ckfinder/userfiles/files/xivijipusexuxilujuwuk.pdfIn PDF document text
    • https://siahotel.com/userfiles/files/gigigikoguximupokeke.pdfIn PDF document text
    • https://cahayaapi1.com/contents//files/lijanunetox.pdfIn PDF document text
    • https://stratasphere.online/userfiles/file/52895395359.pdfIn PDF document text
    • https://sherwoodchamber.org/ckfinder/userfiles/files/75688166064.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607af70fcb80c---56173019349.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f6c0f4e3d5---bopumorazajukim.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160cef926ce647---18948111401.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d47db7b6b7---47117767855.pdfIn PDF document text
    • http://eltdb.com/UserFiles/files/9222099124.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/vixafovixoxoranulonetes.pdfIn PDF document text
    • https://aedwea.com/upload/foto/nevamegexaxelugufezi.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/83986567035.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/valowuzokoxakinunanijika.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/7712312763.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210630092118.pdfIn PDF document text
    • https://visionbrindes.com/admin/fckeditor/userfiles/file/wefudinizebomumilapila.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/zoletewop.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/45ca662f1cf44182be96c2dd18496a20/lexiditowuxiwo.pdfIn PDF document text
    • http://proxima-design.cz/files/file/sawaxiletomipiletikopug.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/bedokijuf.pdfIn PDF document text
    • http://thinhhoanggia.vn/Images_upload/files/vuzupaj.pdfIn PDF document text
    • https://papiratisk.cz/soubory/65700371840.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/3035246590.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c96cff48c45---7505319104.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/adab29abcf31ca882614d78aff93a270/46297981910.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_off000134c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134C5 18920 bytes
SHA-256: 5dfae22b2e66a82aa0c5d3f2a2208e48b27847f58d9b884bf0b73783c95b8e80
font_01_sfnt_off000166a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x166A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017ebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17EBF 9724 bytes
SHA-256: eee5e21bf26feada5794af1135330739a0e80febed026873169a750e13f42110