Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4fc4138138a3bf4…

MALICIOUS

PDF

80.4 KB Created: 2021-10-08 09:03:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0e5e618f5c54dc33ba0928cf0ab17419 SHA-1: eeded2e9c73c2eff2dd2adece64057e272c313dc SHA-256: f4fc4138138a3bf44b89095c1b5de04dcb2c823b84b8b2adeb4f2c936f5aa761
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and a large number of external URIs, many of which are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware via the embedded links. The embedded JavaScript is likely used to facilitate the redirection or obfuscate the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • 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=what+is+a+composite+number+and+a+prime+number PDF link annotation
    • https://floridainvestment.cz/files/file/jukuzuzeke.pdfIn PDF document text
    • https://martan.es/cenavarra_userfiles/files/86258655794.pdfIn PDF document text
    • https://rt-totaalafbouw.nl/userfiles/file/37776339728.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/daxapogogefesitedukoz.pdfIn PDF document text
    • http://sumbulefendiegitimvakfi.com/resimler/files/1006838335.pdfIn PDF document text
    • https://bititechnika.com/uploads/file/zijutabef.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614bd37dd7844---80532734011.pdfIn PDF document text
    • https://isosklo.cz/uploads/13541473921.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/fovebepakadabatojekojonun.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/gerutusura.pdfIn PDF document text
    • http://leprofit.ee/cmsfile/contentfiles/rodati.pdfIn PDF document text
    • http://tdybio.com/uploadfile/file///2021092806100954.pdfIn PDF document text
    • http://progetec.org/userfiles/files/77144020213.pdfIn PDF document text
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/42975977318.pdfIn PDF document text
    • http://pbpharm.com/upload/files/29575943431.pdfIn PDF document text
    • https://812423.situshoki1.com/contents/files/biwizoxerezasomijomi.pdfIn PDF document text
    • https://seeyounow.net/userfiles/file/pixugepawozerisel.pdfIn PDF document text
    • http://hangquangauto.com/files/dilikaxisuzitoxal.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/pegoxufatatimabedu.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/d67ff23e1ad3b5a4bcb5dc9ce2cd2c90/nubifipiputixewegaxas.pdfIn PDF document text
    • https://www.puskinas.lt/ckfinder/userfiles/files/bekuritudimafuvir.pdfIn PDF document text
    • http://idolyokocho.com/js/ckfinder/userfiles/files/gedijiwubupilitadomekuwa.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/69820821478.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/tixomi.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/2344810346.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210905120505_axv9cu.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_off0000d42e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD42E 17968 bytes
SHA-256: 691250b67a5c0f966c5a180090c59b935fc46b500c1eae7715188cab8ff82fea
font_01_sfnt_off00010238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10238 10968 bytes
SHA-256: a4ab8909bbd82279f7e555f0c21cd56410c477a52766b903d51f3a21dc0b5382
font_02_sfnt_off00011b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1