Malicious PDF — malware analysis report

Static analysis result for SHA-256 61d1d79a43aab676…

MALICIOUS

PDF

99.1 KB Created: 2021-06-25 18:18:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e257c604e353bf5371a7da6485923104 SHA-1: 77afec1accaa3e585234352c6335476f2ebf6bdc SHA-256: 61d1d79a43aab67693d473d864cb5aa64cea7c05914e015f4f5c165a7a2c42f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to compromised WordPress sites, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the links and the PDF structure are consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9784

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://archism.ru/uplcv?utm_term=differential+equations+practice+questions
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/ab11a3838bfbd8e66a9b0beb4d3830bd/navikusiwoseruwireseronib.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608240aad73af---wigugumigelas.pdf
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/r02bkb7h44nue753joe65v3j5h/gapixotudodomoguta.pdf
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/5ummaj2eliq5jsku3mlhu7g5us/56966712030.pdf
    • https://chameleoncoupons.com/adgprocessing/uploads/files/watolifomakebu.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/196ee3758650d7b27dfeb19743944c38/38376186908.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d34cab5a68---laxowupudimojigezitanenof.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/a9kff62mkqtum0e55aq28tadr2/96401329780.pdf
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1608105f60b237---24851133428.pdf
    • http://ubest.ru/images/file/94078066186.pdf
    • http://jordanfamilyreunions.com/clients/5/51/51534e3e38036466a76ca8a024fd4923/File/30294869039.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/a6bbc3b3be9f0874bab7ef6bba35090e/zirepemusowexajix.pdf
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d04f803673---79931063248.pdf
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/01b05b93c2266e13132cd36655bc26ae/redijonurodobuviran.pdf
    • https://nnkcreations.com/userfiles/file/45174007847.pdf
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/f77994a770affaf2eb15c31061fb281b/68464462189.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608771a5a6852---6095514967.pdf
    • https://galerie-louise.be/userfiles/files/bezemetavoz.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d916fdcfd1---39450439025.pdf
    • https://dienlanhbachkhoa.info/upload/files/zawusefuk.pdf
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caed29b8862---pejuboluxiriwudem.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/dbh0n0gud6fua19lv3s7e3u8a2/daxasipapun.pdf
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16072ba2ea05fb---rapufevud.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/a5abf35c86a43647657d6ee2d5392754/75935523655.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1d2d0c726---99016466255.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/8e0c09125ef4c4dd127c0548e32dfd11/xoguxeritilufurap.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/jndl7vncq44cj1mnsleivufv51/85517176387.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_off00011f9f.bin
c26e37cde1d3058edf2f9e683fb359c41043250ea063e24c87c40166f561b104
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F9F 17452 bytes
font_01_sfnt_off00014de6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14DE6 16792 bytes
font_02_sfnt_off000165fd.bin
cc29d9b27536e2ecdf31fed2a89ddda780a0b076c7ffa318f99cc16cc7fc00d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x165FD 10720 bytes