Malicious PDF — malware analysis report

Static analysis result for SHA-256 4365bd6a67605221…

MALICIOUS

PDF

93.0 KB Created: 2021-10-08 19:45:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4528e229add318a3ead8deccb3476dcb SHA-1: e9f92f2cdea14b183970cc33c8f32ade1eec06dd SHA-256: 4365bd6a676052219fffa6becbf38b425ca93bf52bfb44fabdec601b1fc8b31c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as a malicious PDF by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to disposable domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior, suggesting a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://ride.hu/images/uploads/files/xesafuvekix.pdf In PDF document text
    • https://nabsangram.com/userfiles/file/4053848489.pdfIn PDF document text
    • http://fiorenzuolatrack.it/userfiles/files/katexef.pdfIn PDF document text
    • http://trendstyleimage.com/uploads/ckfinder/userfiles/files/56665944344.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/womemodefosawexojega.pdfIn PDF document text
    • http://nofatrans-int.com/userfiles/file/duwizafibokol.pdfIn PDF document text
    • http://svb-volleyball.de/userfiles/file/38194208296.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/9658a90ee58a76d2dd1c493878753ba6/75791671895.pdfIn PDF document text
    • https://sgotomotiv.org/upload/files/8245234786.pdfIn PDF document text
    • http://kingkady.com/uploadfile/files/sazuxobowanan.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/6cc5da467e99f8dbd7701137750d93d1/27029081616.pdfIn PDF document text
    • http://artbaget.net/admin/ckfinder/userfiles/files/84656132080.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/fimujizafenenu.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/femabibotifu.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/77176416077.pdfIn PDF document text
    • http://tao-oita.com/admin/upload_filesfile/44995659485.pdfIn PDF document text
    • http://domplus.su/userfiles/files/78025671363.pdfIn PDF document text
    • http://baltyk.recykling-rejs.pl/imgturysta/files/jopur.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/35672362396.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/runaxosebi.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/2937396784.pdfIn PDF document text
    • http://arsvet.ru/img/upload/92639110943.pdfIn PDF document text
    • http://besteva.com/upload/files/duziginuxi.pdfIn PDF document text
    • https://cmoretv.com/userfiles/79439265727.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=cheesy+bubble+and+squeakPDF 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_off000102a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A9 10556 bytes
SHA-256: 6e7b944d1699d713d69dceab3b7f546d1cb5a3cc94b5f97694c2c384818f4d2f
font_01_sfnt_off00011a7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001328e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1328E 19840 bytes
SHA-256: 4bd0e64982379f5756b7ebb6d54d402e438d177c4762a58eb1eebe8e942bcdfe