Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb87333f8fe6ad43…

MALICIOUS

PDF

86.8 KB Created: 2021-09-24 10:46:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2f84868811967a25dc1f93840283e7fe SHA-1: 4a169dc0d8822629248a7f968443d845eb9f52ee SHA-256: cb87333f8fe6ad4316b0e45675696f593627e3828c4ffe204409d5ed0bb31d45
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm or SEO manipulation tactic. The ML classifier strongly indicated maliciousness, and the presence of multiple external links supports a pattern of directing users to potentially harmful or misleading content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://wastran.ru/uplcv?utm_term=how+to+find+sleeping+apps+on+android
    • http://appinaris.net/ckfinder/userfiles/publics/files/zabexikokoromawejore.pdf
    • https://selispin.com/calisma2/files/uploads/suwizuforan.pdf
    • https://absoluteanytime.com/media_file/files/files/balowonamiwomomo.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/161373beb780b4---96716737089.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161400d179baa1---zebimamijedunebibut.pdf
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/17173230640.pdf
    • https://bunexim.dascalita.ro/app/webroot/files/userfiles/files/totajurunofategege.pdf
    • http://mosme.org/uploadfile/files/56972508909.pdf
    • https://museuminiaturesbesalu.com/files/selewovilovodaduvafumezu.pdf
    • http://acrclubinversores.com/files/galeria/files/97431115764.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161462106b2e95---bavewuwajuzebumotibi.pdf
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ba712499e1---70674214724.pdf
    • http://sysquare.com/UserFiles/files/55744005251.pdf
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/c2b9236e0bbefa061d2ab77fa226ac29/wajonijidamatemisud.pdf
    • http://camonetinternational.com/files/file/soxuwosupapu.pdf
    • http://currycornersugarland.com/admin/images/file/56993345382.pdf
    • http://adamlegal.com/userfiles/file/83479390427.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613085240d473---xoxanalemoweb.pdf
    • http://divapharma.com/uploaded/file/nufavidikotuzoxonomewubix.pdf
    • http://maility.pl/_ADRESuserfiles/file/zerakewusoxox.pdf
    • http://dyccpharma.com/upload/files/95092360733.pdf
    • http://htwy.com/upload/file/18504901871.pdf
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0887c6dc0---25103312718.pdf
    • http://sp2wronki.pl/fotki/fotki/file/wenagoxiruteref.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_off0000ef1e.bin
cb4eb0b44d154592fed2fc212461116efad573801c3b7e7651ea270133fa0e4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1E 17540 bytes
font_01_sfnt_off00011c59.bin
2533c41487fed4266f490e9fedfa7475bf5b0333eea0ca245805bfe3845d4959
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C59 10748 bytes
font_02_sfnt_off000134f7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134F7 16792 bytes