Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac61ecc0a1058655…

MALICIOUS

PDF

81.8 KB Created: 2021-09-15 17:17:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aff11608910c57e5f286b178378ef8ea SHA-1: ec850d96ea1833835c75fbbd86f49520d92e09cf SHA-256: ac61ecc0a1058655f4fb9d0363a8277084e8d62516ba5024da96ef1121b774f9
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and external URIs, with a high ML classifier score and ClamAV detection indicating malicious intent. The 'Browser extension / update installation lure' heuristic strongly suggests a social-engineering attack designed to trick the user into executing further malicious code or revealing credentials. While the document body is unreadable, the presence of JavaScript and the lure heuristic point towards a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://www.plain-pied.com/editeur/ckfinder/userfiles/files/41473692968.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/d4ab6c22a29d79b0eccf7ab20620eda2/sorisexogajewikurowotova.pdf
    • https://kcss.hu/korosi/userfiles/file/39741955909.pdf
    • https://meganimal.pt/site/upload/file/56375262662.pdf
    • http://risme.vn/files/perol.pdf
    • https://icbacademy.com/upload/files/rovupivizivodamobivelar.pdf
    • http://thucancakoihikari.com/luutru/files/futemoselufeb.pdf
    • http://acelybio.com/upload/files/69070045742.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/o7b6q8bhktftnu5usmtd6p7633/gofoniroji.pdf
    • https://10playsolutions.com/clients/softklk/documents/_articles_/file/rumesugapakuxa.pdf
    • http://vandofigueiredo.com/userfiles/file///41100608985.pdf
    • http://consoles-a-gagner.com/fckeditor/userfiles/file/96151821826.pdf
    • http://mariopresto.pl/userfiles/file/82589344545.pdf
    • https://anandamsanyal.com/userfiles/file/95670231494.pdf
    • http://basketaci.cz/UserFiles/File/6929782396.pdf
    • https://reformedgeneration.com/userfiles/file/70733365235.pdf
    • https://receptabc.hu/images_banner/files/nudimuxob.pdf
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/nuvuduzusobor.pdf
    • http://corse.annuaire-regional.com/ckfinder/userfiles/files/56031758602.pdf
    • http://consulcongress.it/uploads/assets/file/5879247368.pdf
    • http://kuresi-kaitori.com/upload/content_pic/files/tuxoxadiga.pdf
    • http://ropesadventure.com/d/files/2014143611.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=garry%27s+mod+free+download+chromebook
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/90432886647.pdf
    • https://www.assessment.unibe.ch/app/webroot/js/ckfinder/userfiles/files/wadep.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_off0000d806.bin
30bb654adfe2a0b94935f8f8c9e71196fc4c457a98f10bc093aca89e3473e014
pdf-font-stream PDF embedded font (sfnt) at offset 0xD806 11056 bytes
font_01_sfnt_off0000f1be.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1BE 16792 bytes
font_02_sfnt_off000109d0.bin
8d4dabd33a53fbb4311bea16c0f213d37246dcf94ac83f93aaef4c4b49c1ed99
pdf-font-stream PDF embedded font (sfnt) at offset 0x109D0 18556 bytes