Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb86670f4d9be2a1…

MALICIOUS

PDF

83.3 KB Created: 2021-09-19 07:02:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4f418ab90615c332969af0dafdbb03ff SHA-1: 54c2a44dc809f45ef095cff1167dd6982ca26789 SHA-256: cb86670f4d9be2a127c0d7104642d9f7fb8b122054187911ed5e920de77b77c0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • 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 https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614622154baf1---12403813656.pdf
    • http://www.gulbaharsigorta.com/contentData/file/72765343751.pdf
    • https://media-get.com/userfiles/files/kuzer.pdf
    • http://phonphangschool.com/upload/files/1079037233.pdf
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/b7ed6e437a5dcfbd55f3051ffde65231/93324753395.pdf
    • https://buonoantonio.it/userfiles/file/21385218646.pdf
    • https://rlmahtani.com/userfiles/files/lebibijuwarulupik.pdf
    • https://dwitunggaljaya.com/sitefiles/file/nozavevep.pdf
    • http://trumoi-khutrung.com/upload/files/gonavoli.pdf
    • https://ochronaskory.pl/pliki_user/File/titurofoxanusen.pdf
    • http://retailcop.ca/files/kedesara.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f52da61b85---webamadebo.pdf
    • http://gndpta.eu/news_objects/files/21676017490.pdf
    • http://angelcabrera.com/FCKfiles/file/44829127747.pdf
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/berubakilavipu.pdf
    • http://chinawin-consult.com/userfiles/jatipanutazo.pdf
    • https://infoenergie-loire.org/userfiles/file/42934362564.pdf
    • http://lexprikson.com/admin/style/images/userfiles/file/fepepozojovisuwugu.pdf
    • https://quangcaowebsite.xemlaco.com/uploads/files/32791348246.pdf
    • http://koryosushi.com/uploads/files/batazasuzanufaxakajax.pdf
    • http://sinosteelcode.com/filespath/files/20210903202009.pdf
    • http://cathugo.de/res/wysiwyg/file/44442388148.pdf
    • https://www.colegiodomus.com.br/js/ckfinder/userfiles/files/kivunet.pdf
    • http://vitalbafitnessclub.eu/userfiles/files/vajujuliduwox.pdf
    • http://geo-equipe.it/userfiles/files/pifawedeziruninujinowu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=play+mp3+on+android
    • 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_off0000e474.bin
972d381c6bc25a508ce63254a6c74ef7eaafe47ec1959a128b43cef1175c11f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xE474 16900 bytes
font_01_sfnt_off00011028.bin
6bdb8c3b32162c1a51aa0f105c50b09f448c2218b557276dbb189ea65b07beee
pdf-font-stream PDF embedded font (sfnt) at offset 0x11028 10444 bytes
font_02_sfnt_off000127ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127BA 16792 bytes