Malicious PDF — malware analysis report

Static analysis result for SHA-256 846b988ec4be4338…

MALICIOUS

PDF

88.0 KB Created: 2021-09-18 18:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d9f705da10eaee20da92f4e6b0df9d13 SHA-1: 1e6d7096846f7a004071c88b0dd963c1d9b98a47 SHA-256: 846b988ec4be4338bf059126ce55066115db2dadecb01f9e391997337c005c5d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicative of a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF used for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://robwalker.net/fckupload/file/98368489664.pdf In PDF document text
    • http://innovatepc.com/userfiles/file/rumupitefipukitevofe.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16136c95901f04---vufonedorevonok.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/limexudesuganajenu.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/kudivowuxak.pdfIn PDF document text
    • http://haphadoor.com/upload/files/44084078903.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/64598937743.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/2021971638255462.pdfIn PDF document text
    • http://peetersinstallatietechniek.nl/upload/files/sodukusezabawezotu.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/xatip.pdfIn PDF document text
    • http://lycee-elm.com/userfiles/file/33267983796.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614163e9636db---zupolotuxedawozizul.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/vafuzekefe.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/terofolajawetapevixikodip.pdfIn PDF document text
    • http://langfordfinancialservices.com/userfiles/files/kabiritemalefotutisulave.pdfIn PDF document text
    • https://infotechloyalty.com/bot/ckfinder/uf/files/tufukufawegudafivi.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2c1972ec4---83113108527.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/zenom.pdfIn PDF document text
    • http://wellnesszeewolde.nl/site/data/ws/files/58660789558.pdfIn PDF document text
    • http://gaudi.tw/upload/files/55042841932.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/52066495672.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ares+gratis+para+android+en+espa%C3%B1olPDF 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_off0000eaf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF1 20536 bytes
SHA-256: ef46ce7058b30e2f0e2a052d72ba7b4278d8dd797f25834b254f2a58a9530681
font_01_sfnt_off00011f93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000137aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137AA 10756 bytes
SHA-256: 28ae9b160630e284697da08495c3a2979f5be2afc3b7798140051492647d2418