Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8164e40ebf99080…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 06:25:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c25e991be6c8bf67abf1aa9a0a0765a9 SHA-1: a7ad395480d31ab5b2da8d0b204fae69f9eaf344 SHA-256: d8164e40ebf99080fc198947c38e77baf1ff941aba8f81065274f4fb84ac512e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URI heuristics and link farm indicators reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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=messenger+apk+updated PDF link annotation
    • http://historia-bfured.hu/userfiles/file/47024747566.pdfIn PDF document text
    • http://373113.linker.tw/files/puxamibazafa.pdfIn PDF document text
    • https://ipkameros.lt/userfiles/file/vetoramidenevojes.pdfIn PDF document text
    • http://mitroc.com/userfiles/file/dononuluxudebular.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/161448ab66df60---80814798825.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/bekijuritukokevexa.pdfIn PDF document text
    • http://fullx.net/files/modomisubixelojemebivur.pdfIn PDF document text
    • https://eniedu.com/data/file/20210904050719.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/67145145065.pdfIn PDF document text
    • https://turbooto.vn/upload/files/xibinosekoxa.pdfIn PDF document text
    • https://rajaketiga.com/contents/files/taderomoka.pdfIn PDF document text
    • https://tatvan.in/userfiles/file/benubolutawa.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16140eb934b7b8---729218504.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/22325754635.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613467901a2d8---16050855263.pdfIn PDF document text
    • http://solis.altrodesign.eu/ckfinder/userfiles/files/zimenejunoxexebapo.pdfIn PDF document text
    • http://pivotal-technologies.com/userfiles/file/68625768147.pdfIn PDF document text
    • https://rafautama.com/uploads/file/16281567660.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/vipewusukuresimukagow.pdfIn PDF document text
    • https://nhatngudongkinh.com/upload/ckupload/files/43879089159.pdfIn PDF document text
    • http://www.badischer-kunstverein.de/ckfinder/userfiles/files/60097676072.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/13669855302.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_off0000dcf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF6 16896 bytes
SHA-256: 6ed2e1a69419b45b21cbab62ec60ced93cbb8e03ba033da994a8d503d4f8b947
font_01_sfnt_off000108c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C9 10496 bytes
SHA-256: 91c6ee96f92b3431dce6f5706ed0ee69208d68116a5ddac2668352a48c8aa1d9
font_02_sfnt_off0001209e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1209E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1