Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fa510ea939d3bcd…

MALICIOUS

PDF

81.2 KB Created: 2021-09-16 01:37:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f4f640cda337a941d0a4cd0e90ef55a9 SHA-1: 9d5cfcf0e6e69645b13e35e2eb4d0966236c2581 SHA-256: 4fa510ea939d3bcdda0b0f0b1cc5e5b97e160bbdbfa883bb6febf30bf67e0fbe
142 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external links, including one pointing to a potential download URL, suggests the document is designed to exploit vulnerabilities or trick the user into downloading a secondary payload. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the idea that the document is part of a malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://catamma.ru/uplcv?utm_term=3d+live+wallpaper+hd+for+pc+free+download PDF link annotation
    • http://soleilboo.com/images/uploads/files/20029923368.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/jatetudamenupurose.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/59592815264.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/pufonilin.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/wozigagareta.pdfIn PDF document text
    • https://jungleflightchiangmai.jungle-flight.com/Uploads/files/19501004768.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613127f387a42---19891379061.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/zekamibanopetojalo.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/papoxibivumosusokogudib.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/44354579837.pdfIn PDF document text
    • http://wwstationery.com/files/file/4639575411.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/fusaluvafixegarapop.pdfIn PDF document text
    • http://firesecurity.sk/userfiles/file/9528737994.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/bisutisulo.pdfIn PDF document text
    • http://namngonviet.com/user-/files/49246807093.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e64894f794---lugubuxixowabimilidid.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/jonodexawenawatinaguri.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/sifeludemutifuke.pdfIn PDF document text
    • http://www.msjcongregation.org/www/js/ckfinder/userfiles/files/funafutilela.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/64233681596.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/tubadotowojamodalaromewe.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_off0000d9a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A7 17376 bytes
SHA-256: 7556d3f70bec54ad24e10db288223cb4eb9fbd8734495749987063650195d379
font_01_sfnt_off000106e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ef8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF8 10676 bytes
SHA-256: 371d00ecbf270cadb26b4bb8574a00b00aebd30113d2081f31e8a9357805223c