Malicious PDF — malware analysis report

Static analysis result for SHA-256 39af3d279a30b917…

MALICIOUS

PDF

76.6 KB Created: 2021-07-21 05:07:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1fb33e097d749eb120f3469c554e60a5 SHA-1: 38808495454b966bb38d11581e7d1c655a4bee62 SHA-256: 39af3d279a30b9170ac4d5b016e18383e908922457f77dac737ff279a4e68e1c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised WordPress installations, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary attack pattern involves directing users to these compromised sites, which may host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/j9nom7j8eskvc1v906rgg6g2lk/gafimosilepubav.pdf
    • http://dongshengcable.com/images/upload/File/vivuwuduzobixonobu.pdf
    • http://zaun-produzent.de/userfiles/file/84273812054.pdf
    • https://manajrgvaaradhi.com/cms-uploads/files/lewoke.pdf
    • http://usmleworkout.com/files/file/32998568183.pdf
    • http://woodwork.pl/ubezpiecz/obrazy/file/96695890154.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16077f1aa96fc4---58561360496.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1e2caa74e---19345881110.pdf
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/a6522855c8c0249b48a47072563dd271/96741976979.pdf
    • https://digireg.lu/upload/lelomagukenakerorofevaw.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/7303e8224bcfefcab3003972fedfc1ba/32442667559.pdf
    • http://www.motionmantra.com/userfiles/files/wijudezuzavazaxa.pdf
    • http://thaisomboonautopart.com/userfiles/files/bupalubu.pdf
    • http://ecohouse-lab.com/userfiles/file/36252178119.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160916826aadd5---62592532730.pdf
    • https://topupdana.com/contents//files/rapifa.pdf
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/5df91f893ed047d5e34dcf8acaafed42/17015086058.pdf
    • http://thebrownsfamilyreunion2008.com/clients/81208/File/27840011286.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080e98f64b30---34982335512.pdf
    • http://allasclub.com/campannas/file/bovofazutaperigeze.pdf
    • http://sieuthicayxanh.vn/webroot/img/files/juvilizimiw.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607433d20e871---tosodaxo.pdf
    • https://p87.hu/files/99804976609.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=vhdl+books+pdf+download
    • 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_off0000c8d3.bin
2f0441f119326009ab4d265afc68ba0da1cebba42562a5108c40680f504b8f5c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8D3 17232 bytes
font_01_sfnt_off0000f5d6.bin
934996532cf19f1828c602ef234d217a1a9b305e6faea2cc655ea39f0b5a75e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D6 10460 bytes
font_02_sfnt_off00010d55.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D55 16792 bytes