Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb1fbcaaf8ce4b08…

MALICIOUS

PDF

72.2 KB Created: 2021-07-18 23:42:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4b89dbeff6df0ae0351ad8f667ca7fb1 SHA-1: a2f537fc93c5a717acaf42c87802224208e1466f SHA-256: cb1fbcaaf8ce4b08ef4e8f1892c69f902943977583e212e08a1aaf5521ebeea7
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the ultimate destination or leverage compromised infrastructure. The presence of multiple PDF-specific heuristics related to URI and link farms further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://fenixfalt.com/userfiles/file/mekajedojakikolesabibiz.pdf In PDF document text
    • http://koreaseowon.com/ckupload/files/kebisudibuf.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090c39b02f12---wotupowekibabifosezira.pdfIn PDF document text
    • http://goldmustang.com/files/files/zogirodezibegavetidefami.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/tajiban.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/00fc9f5b47b9b7186f65f438c89aa325/28177592131.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/lunovikesiduvusoto.pdfIn PDF document text
    • http://faw-asia.com/image/upload/files/wewevilawitatu.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/fumijinojuxugexoveteliwef.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d06ea39a77---18156339136.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/a9ff2ffdc4a4e02c5ec23c7f8108b301/venef.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/5b7d4d1609cac77544877cdd93579f77/ziturefuvuvofosov.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/serulomij.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160757e29cac13---fewipigobazo.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/nimofepetibefi.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/f8f424533605151a03104ed5558e7e90/14789367891.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/fc7h7gfp6jln73uh7639iq9f5e/vadapodisofinulefokuromis.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/us8dku7fc4grik8e8qbhemc8l5/44519434081.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b58967b4246---71311415826.pdfIn PDF document text
    • https://study4student.com/cache/fck_files/file/getirazedusojijunopotojir.pdfIn PDF document text
    • http://haustechnik-hagenauer.at/wepubiwugosar.pdfIn PDF document text
    • http://nordicaluminium.ru/userfiles/file/pisiwikivogovizawisifeno.pdfIn PDF document text
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/52310489917.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/af1d0fc4f9bd2a6439a2dcf0c2659444/22059451679.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=molecular+mass+of+sodium+sulphate+decahydratePDF link annotation
    • 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_off0000b7a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB4 16364 bytes
SHA-256: 6c94ffa63a2e8d0aeb0526f8afbf6fe7792a1777adeaa7716cf0ee8e0fcfc787
font_02_sfnt_off0000f9b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B4 10988 bytes
SHA-256: 7d81f1a4bb28a861f654b91100a998a037d60ce4c9a820bce8c7b3ce31169e16