Malicious PDF — malware analysis report

Static analysis result for SHA-256 c856c77283b4ec8f…

MALICIOUS

PDF

70.3 KB Created: 2021-09-27 01:53:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c0787a1ede2a06bfa197c2d692ffb98c SHA-1: 8fcbcc19fe4342f6f49890508a64abc031c578f8 SHA-256: c856c77283b4ec8fd7b84ae6a812d9cbe2d79bad8060c72e2495ffc08af0865d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. It also features a link farm pointing to multiple disposable hosting domains, including compromised CMS upload directories, which are likely used to host phishing pages or further malware. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 http://polymer-optix.de/userfiles/file/25699499208.pdf
    • https://thietkeweblongan.com/upload/files/podifano.pdf
    • http://grgct.com/ckfinder/userfiles/files/51953483205.pdf
    • http://urotunisia.com/uploads/FCK_files/file/numumelesinujeduko.pdf
    • http://villabrown.it/userfiles/files/53383633209.pdf
    • https://www.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/49789932150.pdf
    • http://peoplefineart.com/assets/202109/files/20210903093052446997.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/d938443033e7f9d9e9895cfcc7664b87/61307305463.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/96745675988.pdf
    • http://taxfreepoint.com/file/4743546391.pdf
    • http://longarmacademy.net/fckeditor/userfiles/file/zetezokuzuzatominilefed.pdf
    • http://sb555.com/photo/file/jojofatejawegesaw.pdf
    • http://agierresrl.it/userfiles/files/5139050347.pdf
    • http://bukharajohnscreek.com/sites/default/files/file/surogoregewarexafisubej.pdf
    • http://www.binghan.my/userfiles/file/wufula.pdf
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/kujorumusomerozino.pdf
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/d43beru4foem6js2c3oh5hsesf/putivog.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/052a2872b16d94aaa5bd678752232437/gusesavekobixugikinewug.pdf
    • http://qdjshg.com/files/file/nupaluj.pdf
    • http://mama.plovdivweek.com/js/ckfinder/userfiles/files/kojemivipi.pdf
    • https://manajrgvaaradhi.com/cms-uploads/files/27105888804.pdf
    • https://gedayapi.com/userfiles/file/nubotetelofibozaman.pdf
    • http://wpchkg.com/upload/image/file/kuropojanagov.pdf
    • https://parlagame.net/calisma2/files/uploads/metoneze.pdf
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/99fd9a856b84f6768de0245217383a94/zofikekozowideduxi.pdf
    • http://campingwithconvenience.com/files/files/80149015028.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=dua+for+healing+sickness
    • 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_off0000b4fd.bin
d599ed82646773cf064454c7fc10d586a1d6476fe716d1e7443e21e79304842f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4FD 10708 bytes
font_01_sfnt_off0000cd78.bin
32e40a620f099e68efffd536a2ecd7b9e065b1fb268561568e48c35653b75f09
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD78 14980 bytes
font_02_sfnt_off0000f350.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF350 16792 bytes