Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ba6e8c64b53b14…

MALICIOUS

PDF

83.9 KB Created: 2021-10-04 19:32:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: bba223d6be1696e8f79492c1b8048362 SHA-1: 3636a2c9564e4340b60cf6c786ef288b1d1bcac4 SHA-256: 51ba6e8c64b53b148fc32fe58d5b5d7c8c161e32e3c27b23acde46b319c6c036
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to redirect users to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://ketchas.ru/uplcv?utm_term=adipocytes+meaning+in+tamil PDF link annotation
    • https://bitree.ru/ckfinder/userfiles/files/14110082088.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/d7b78a5ac3cd447a9b90afa2e0537d51/movosabuguliwo.pdfIn PDF document text
    • https://0900107678.com/upload/file/jusezug.pdfIn PDF document text
    • http://reyazahmad.bscsaoner.in/ckfinder/userfiles/files/vakipijukifipaf.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/7393940032.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/35974870620.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613c09c150cda---ketifadedakoso.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/5967990117.pdfIn PDF document text
    • https://miltonmattox.com/userfiles/file/buxarobifesasetabapiraj.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/tesiposinejemo.pdfIn PDF document text
    • http://chanhbon.vn/media/ftp/file/sozewununironoxeguno.pdfIn PDF document text
    • https://triosms.com/userfiles/file/rojupam.pdfIn PDF document text
    • https://wisestudentz.com/userfiles/file/suziwomikagiluz.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/jagakazifip.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1632780623.pdfIn PDF document text
    • https://ptogel1.com/contents/files/newijizagafuxa.pdfIn PDF document text
    • http://www.luna1956.com/images/library/File/62108166995.pdfIn PDF document text
    • http://xn--franzsischebulldoggen-lec.eu/userfiles/file/demopasowofajibigekajuta.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/kejejerifixixoporute.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/sufemonixuwuviviboxusus.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/rubawekazaradat.pdfIn PDF document text
    • http://homeloanz.net/images/e/file/pumaziwugimomopowezitix.pdfIn PDF document text
    • https://zemtechnika.lt/public/site/0files/siwun.pdfIn PDF document text
    • http://ctm.it/userfiles/file/54374506132.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_off0000db90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB90 10852 bytes
SHA-256: b2390163391c2661c5b26f93a8ecb10ab15eccafb5953af18f388a8d870b210c
font_01_sfnt_off0000f46d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF46D 20800 bytes
SHA-256: 9bc8f89ee3793dc8cef16c1d93a53b8fe451a948ab2218987569a1b57a43f661
font_02_sfnt_off00012a84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1