Malicious PDF — malware analysis report

Static analysis result for SHA-256 8395737ef1dd6635…

MALICIOUS

PDF

76.8 KB Created: 2021-09-02 01:32:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d400509b93630ac5ee15fdbdad672e9 SHA-1: 6389e129e595fc36f5fcaa303bee663abaf41012 SHA-256: 8395737ef1dd66358b41d838ea3196612249b55a1296a310ee3ffb756d40590b
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which are identified as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these redirect links. No scripts were extracted, and the document body was unreadable, but the link farm structure is a clear indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9945

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jordanadams.com/ckfinder/userfiles/files/8507854850.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ffe9466d5---87580893504.pdf
    • http://ez-surveying.com/htdocs/cljr/data/files/lalikowijowexukafeli.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b437dc784d4---15310144834.pdf
    • https://lasanisports.com/files/wunizumeluwazovidatebuj.pdf
    • https://carcable-bg.com/uploads/pictures/files/84874370763.pdf
    • http://ttlh.vn/storage/ckfinder/files/witinizu.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/25485434699.pdf
    • https://nmg.lv/img/uploads/files/tujiku.pdf
    • http://ahcxdq.com/uploads/file/020223485807.pdf
    • http://zamel2.pl/userfiles/file/sebejegakiwumum.pdf
    • http://mp-hd.de/data/aktualnosci_imgs/file/wikatotovo.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/09mtapen8dmg2jeed626rcsbhu/kevovetedobafi.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/11ac3d6dc1b167f06ae96a1b1fcb7a25/fitipesaj.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/16088ee623e028---88767445857.pdf
    • http://gesundezellen.de/neu/userfiles/file/39206819672.pdf
    • https://pachetedeturism.ro/images/files/robagopowojobapi.pdf
    • https://inwestorfinanse.pl/userfiles/file/risipoveluxeliba.pdf
    • http://banhangcongnghe.com/upload/FCK/file/sowumidegusosag.pdf
    • https://autoradiator.mn/uploads/ckfinder/files/70538491631.pdf
    • http://xinyaoqiye.com/upload_fck/file/2021-6-30/20210630053751172897.pdf
    • http://clarkstownhs64.com/clients/2/25/255c49a504cbad61718694d8b78dfcdd/File/52923607553.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d1152d6ab---vezem.pdf
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/595c1cd81f9919c415578d3757387ab6/90998806766.pdf
    • http://shesob.com/file/files/22710682386.pdf
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba90a447d1---sovogeru.pdf
    • http://4998horo.gmmwireless.com/contents/files/85311673155.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=another+word+for+strength+and+courage
    • 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_off0000c8f2.bin
51c5af364c654cd7ebda41bfad53861096be6df2ad4d3c51ecab2b93fc27b1eb
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8F2 17216 bytes
font_01_sfnt_off0000f401.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF401 16792 bytes
font_02_sfnt_off00010c18.bin
5a153074e3c3e33025354d5815656b9eff30f32923506a1916984062d31999ea
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C18 10784 bytes