Malicious PDF — malware analysis report

Static analysis result for SHA-256 139b5aadda06c7fc…

MALICIOUS

PDF

89.2 KB Created: 2021-09-12 21:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c079510cecf908810fce3a79b34ad7cf SHA-1: 273a66737f65dc9e76619bf46b93d87c91d32615 SHA-256: 139b5aadda06c7fc9a48337607e515bb815125133019188c5b7ccc1fec7439ea
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which point to link farms on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malicious content. The presence of embedded JavaScript suggests an attempt to exploit vulnerabilities or execute malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://baoholaodong24.com/userfiles/file/borosejojomibopurom.pdf In PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/62067524663.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/92714136888.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/1196988176136477b1ecda.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/53985492683.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/18869731733.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/11683012544.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/74774166252.pdfIn PDF document text
    • https://rrr71.ru/upload_picture/zonadowiboni.pdfIn PDF document text
    • http://kxxbs.com/uploadfiles/file/a/81822164240.pdfIn PDF document text
    • https://lotusmarinevn.com/upload/files/61216859621.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/13281986795.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210908002034_1261205183.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/29947081249.pdfIn PDF document text
    • https://alperbehang.nl/userfiles/file/14995795723.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613422cb392d0---nemudoxasemozuzijarovi.pdfIn PDF document text
    • http://ossokahve.com/upload/file/kesakerab.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/mulitat.pdfIn PDF document text
    • https://magicdiscoradio.hu/userfiles/file/75190910955.pdfIn PDF document text
    • https://dunaweb.co/bg_image/files/84607530621.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/72855655513.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/mosire.pdfIn PDF document text
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/80848700326.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/66569781107.pdfIn PDF document text
    • http://technoauto.jp/js/upload/files/lofujenafuwevut.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613df1515b853---19082994886.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=where+can+i+watch+now+you+see+mePDF 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_off0000f5a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A8 18716 bytes
SHA-256: 1ecbeaf102465a72a685b4cefdaeab76a6b1f170e60d03329e6fbf150ee8d053
font_01_sfnt_off000125db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013df2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DF2 10740 bytes
SHA-256: 6360e619ecde032642ebf0f039cfc9dacf0f82606739c3de0c689f86e435893e