Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec859c353760cf3c…

MALICIOUS

PDF

69.1 KB Created: 2021-09-25 19:51:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e0278264efd22bf90d00f00923e50650 SHA-1: 90ad5108e832cb13eaa3202be82862742a8ce37f SHA-256: ec859c353760cf3c232bfe344b0d01bc0f042b7c5f2566aaa288057962212cb0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to external websites, 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. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 5

  • 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.
  • 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://laborke.ru/uplcv?utm_term=restrict+games+on+android PDF link annotation
    • https://cakenflowersonline.com/userfiles/file/89129358399.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210905182945.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/40413839188.pdfIn PDF document text
    • http://ingatlantv.tv/userfiles/files/73927273181.pdfIn PDF document text
    • https://groupits.cm/uploads/fck/file/vexubukutelureliposuge.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/1145154725.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/447959162.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/jivejotawuw.pdfIn PDF document text
    • http://dallard.fr/ressource/site-image/files/gujepobufum.pdfIn PDF document text
    • http://oasishs.com/uploads/files/20210902_005513.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202109102051549256.pdfIn PDF document text
    • http://mercuresamuichaweng.com/admin/file/68017630931.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/9308027001.pdfIn PDF document text
    • https://network-italia.com/file/31827329303.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/11145404699.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/razezejarepijekuwuj.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/3503775568.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/mufudixuxizuwadibuvag.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614286b123683---dabopowugetobozakepu.pdfIn PDF document text
    • https://esvigo.com/upload/files/61170640447.pdfIn PDF document text
    • http://presssimayeshahr.ir/pic/file/renig.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1614110de77135---10601574664.pdfIn PDF document text
    • http://v-lukomorie.com/uploader/files/64774258450.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/wesafidivirawem.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/78109550764.pdfIn PDF document text
    • https://matharu.ae/userfiles/file/70053660912.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_off0000b231.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB231 10712 bytes
SHA-256: b90c0a10bb9bc5b90b10e21df6b54a2831b5eed4c8d54121e89096b253db5356
font_01_sfnt_off0000caa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e2b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B2 14328 bytes
SHA-256: 63574075cde9ae8bd7f7e81dd2f490d01cf27bb47b25244da8fbb8713597e0b7