Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba6374f252448ff9…

MALICIOUS

PDF

80.4 KB Created: 2021-09-12 22:36:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9fd97e5ef83a2e8b4d5c3c8cb07197aa SHA-1: 6b416122f31709a641889337c4b7571a91170139 SHA-256: ba6374f252448ff914df087767b203e57fdc19a2049ae61e7b81a7abeaddcb3e
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The presence of numerous external URIs, including a link farm heuristic, further suggests a phishing or malware distribution attempt. The embedded JavaScript is likely intended to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6443

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://taiwan-tiaya.com/upload/tiaya_official/files/15180052484.pdf In PDF document text
    • http://elitsatodorova.com/uploadfiles/file/57883991101.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/68675641300.pdfIn PDF document text
    • https://estatecambodia.com/htdocs/cljr/data/files/goxapagududadija.pdfIn PDF document text
    • https://aramlasmerok.hu/uploads/file/farofagirumugubewu.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/2t3iuoi6gs3h3aqjqlfde946j3/walana.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/wototodupobawogalipu.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/pejezozo.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/tolarewateluvuwo.pdfIn PDF document text
    • https://goacetours.com/ckfinder/userfiles/files/59073316672.pdfIn PDF document text
    • https://ip-kamera-rendszer.hu/ckfinder/userfiles/files/18721683575.pdfIn PDF document text
    • http://mundori.com/js/ckfinder/userfiles/files/jibologijozipuvavagikoba.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/97423312001.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/nivokexezuzaborimifuxumox.pdfIn PDF document text
    • http://surestegc.org/documentos/file/69196037810.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/20887726050.pdfIn PDF document text
    • https://airxps.com/userfiles/files/velisidotixunaxofivul.pdfIn PDF document text
    • https://www.rougeindigo.com/ckfinder/userfiles/files/sedezaxilakaxokotagulimut.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109100318316805.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/tuxigetupireriwoxegowafa.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/xiwilaxumudidu.pdfIn PDF document text
    • http://simoncaulkin.com/images/77081231716.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/71847303416.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/nutid.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613548953269f---todabuxijelekamov.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/14639138273.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=english+vinglish+full+movie+downloadPDF link annotation
    • 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_off0000de86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE86 10840 bytes
SHA-256: 902aec9e16713d57049ec12fff2e8a81ee222e5e04cff91897eda3b4153dcfc1
font_01_sfnt_off0000f72a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3C 17236 bytes
SHA-256: a31e14994976422c2f3158037479d5bf48af09c66cbb25a891faba4a3ef2b782