Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cf3b65becc264ba…

MALICIOUS

PDF

78.9 KB Created: 2021-09-17 09:12:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 57eed16610350975d0112a0ec6fc5a46 SHA-1: 34535909963d4ee8addb112601776dd41585c980 SHA-256: 8cf3b65becc264ba3c40cf2c5a630a691c531f8ff9bd45f7db51eaff270a4601
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the presence of external URIs and the link farm nature suggest an attempt to redirect users to malicious sites, likely as part of a phishing or scam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/fixibomasakud.pdf In PDF document text
    • http://jjmcp.jp/userfiles/Image/file/14906358073.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/tb3kgk3ivng6h8od7ongrvqqfk/nodalegulobunimuvipivopuw.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/53569626312.pdfIn PDF document text
    • http://slsnn.ru/content/files/8764915948.pdfIn PDF document text
    • https://roshnaai.com/ckfinder/userfiles/files/71968773215.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/fujifobojuzanonodokog.pdfIn PDF document text
    • http://ets-sptk.ru/pic/file/46502018961.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/94434682242.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cbbb0c3633---dezizoj.pdfIn PDF document text
    • https://zibarajabi.com/cache/fck_files/file/5463938913.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/16077202433.pdfIn PDF document text
    • http://www.reeder.ee/files/filemanager/mafuje.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/xebiwusugeniresalabolada.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/sovak.pdfIn PDF document text
    • http://centrons.com/uploaded/file/1856470775613046eea385b.pdfIn PDF document text
    • http://sm300159.agchost.com/userfiles/files/51462061595.pdfIn PDF document text
    • http://noithatachau.vn/webroot/img/files/xoxigivexowatolilupij.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/maperekebabokujedejebika.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/gizikunidefabonagum.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/fenurebamenuviv.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/53876081808.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/nojazejezosaj.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210909200017.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=english+for+business+administration+pdfPDF 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_off0000d50a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD50A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED1C 15356 bytes
SHA-256: f66975f1537dc17a9b6c85b58cbab65196725cce8a19d71e4c28cf63c3c38acb
font_02_sfnt_off00011442.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11442 11168 bytes
SHA-256: 5155cdd70e16b5f597b9a027abf462e04f6d83c64990a4d200171a5e9404fcae