Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b44d52410aaedbc…

MALICIOUS

PDF

87.3 KB Created: 2021-09-12 02:36:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e5168fcfd422b5e56b7d2c353d63b5f2 SHA-1: 6155b1cfcffbbcdfedd2d0dedf618612e54e87b1 SHA-256: 9b44d52410aaedbcd68b047101c6659459e4a7c60104479a0f5841237fa1a52d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to external websites. Several heuristics indicate that these links are part of a link farm, with some hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://chinastom.ru/userfiles/file/pegugidakinojifarobafim.pdf In PDF document text
    • http://innotack.com/userfiles/files/45404076951.pdfIn PDF document text
    • https://lanegarrett.net/userfiles/file/49438612721.pdfIn PDF document text
    • http://ilkjv.com/Images/Media/files/43877501864.pdfIn PDF document text
    • http://blueview.nl/app/webroot/files/userfiles/files/dunenujudepavilirukabeki.pdfIn PDF document text
    • http://taociren.com/upload/file/210911020343773501j6gor8ua9onc.pdfIn PDF document text
    • http://asqcert.net/files/files/jategudugubobix.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135aad28b490---52166379920.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/fomar.pdfIn PDF document text
    • http://tao-ssct.org/data/upload/file/doxuredodovaridatejaxogo.pdfIn PDF document text
    • https://airxps.com/userfiles/files/75857872052.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/86681039541.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161357795d0a9f---49490260125.pdfIn PDF document text
    • http://4rrecycle.com/files/file/90649757870.pdfIn PDF document text
    • http://nemeckystrakac.sk/editor_uploads/files/bunifufivorufolokarexil.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16131f5588a6b7---92640959908.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/83663a4d5c6ef5a756f0e5ab8efec8a0/pujasademexejutafon.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210905184642.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe11e82263---zizifipubojisezo.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/36848063140.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/b469752c1cc30cb57377bc88262e237a/sadubuwegapexu.pdfIn PDF document text
    • https://millersexpress.com/userfiles/file/44516016924.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/1u4sanq6ivrv050vgl5i0h91am/woxefu.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/tuviliponikujurapom.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/76441412635.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=ben+10+omniverse+2+for+androidPDF 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_off0000effe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFFE 10784 bytes
SHA-256: dd23ff93cea4ffd5762a4b238d9c811c0eafa1f72e2c83d95b60327d0125dd29
font_01_sfnt_off000108f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12103 17672 bytes
SHA-256: f1f4b2a95d076a7562f75f64bbde5490700ca6b67390e792d0fee8320c012600