Malicious PDF — malware analysis report

Static analysis result for SHA-256 721cb5a5f77400f4…

MALICIOUS

PDF

77.1 KB Created: 2021-09-23 10:05:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c91061317cad4b429dbec04347d7f67 SHA-1: 0c4133de6c176723eea1494acb649e993912ed8b SHA-256: 721cb5a5f77400f4055c12b1f87ed9c0cf2464f6fe667386e2125a57eb07a91a
156 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious. It functions as a link farm, containing numerous external URIs that point to various websites, many of which appear to be compromised or hosted on disposable infrastructure. The primary purpose seems to be directing users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://nomylo.ru/uplcv?utm_term=rally+fury+best+car
    • https://chennothinterios.com/uploads/file/85273981955.pdf
    • http://hejia-ele.net/upload/nibusej.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161360db942812---natujudajewemiput.pdf
    • http://blekinge.boj.se/uploads/userfiles/files/12614328437.pdf
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/ruzetinadanugotinan.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140cea4f1be3---23177124099.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c27bc50d5c---25093593969.pdf
    • https://stradatextiles.com/upload/ckfinder/files/loravanidusukirivekaga.pdf
    • http://drzwiukryte.pl/userfiles/file/43859203590.pdf
    • https://gibidesign.com/fckfiles/file/82051886814.pdf
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/gsvdg9tpqeost138q60ics0fbd/perivebexofe.pdf
    • http://kotolantopeni.cz/file/62584976461.pdf
    • https://tedesco.pl/userfiles/file/xuxaviba.pdf
    • https://renebeumer.nl/userfiles/file/54443864318.pdf
    • http://mauthietkedep.info/upload/files/25108124023.pdf
    • https://cailux.lu/userfiles/files/gozamiweput.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/f2002d9396934ff82d461b30287c5b7f/28129324687.pdf
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/pbrku49ds4g8fg1v08esfqmth0/totipa.pdf
    • http://hmed.vn/upload/files/zapatevulufowisosixu.pdf
    • http://www.petercar0937494634.com/upload/img/files/perawekuvogekeromegevitij.pdf
    • https://pianotuningdarwin.com/userfiles/files/28841618071.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613947f654a35---93258224693.pdf
    • http://dentish.ru/ckfinder/userfiles/files/voworu.pdf
    • https://topinsolventa.ro/userfiles/file/xikaki.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c58c.bin
69d2d6cd4f426b4199a1ac72a63732aa6770f79fe5f02f8ce0c5972fabb58bfb
pdf-font-stream PDF embedded font (sfnt) at offset 0xC58C 10412 bytes
font_01_sfnt_off0000dd64.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD64 16792 bytes
font_02_sfnt_off0000f576.bin
2bcb81435c19405070d0b53897438ce0ff31eea7522f0acb44b7cf78623757e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xF576 19208 bytes