Malicious PDF — malware analysis report

Static analysis result for SHA-256 f39949cb1c47fc40…

MALICIOUS

PDF

87.9 KB Created: 2021-07-12 17:24:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65a24dac44eb12d358e96f646e91a0ba SHA-1: a0e855dc37137c9486ce001b5441ffe0558f9f8e SHA-256: f39949cb1c47fc40b25d6219701aa51f0b5b315b6063b7120c43fb799d227c1d
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting, suggesting it functions as a link farm to redirect users to potentially harmful content. The heuristic firings indicate a pattern of using compromised CMS uploads and link farms, likely to obscure the ultimate destination of the malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://pistant.ru/uplcv?utm_term=mighty+mighty+d+block
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160813b6486905---43854365420.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609a281bc9290---50275672144.pdf
    • http://uniroll.pl/user_images/file/87698244532.pdf
    • http://brucemsmithlaw.com/clients/e/e2/e252bfde01ef004f685a9648d307a4b9/File/22129614497.pdf
    • http://111-orte.de/testarea/cwsCMSlight/media/files/bolajexomesuj.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/a5f70c6fdb8f112859b55e48b937e0f5/34110916236.pdf
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/dc8cbaf6d6bc8c086df541a916d83b31/20516902254.pdf
    • https://brigitte-farner.ch/userfiles/files/64702049758.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16081291337605---kefivamameb.pdf
    • https://gujaratisamajparis.org/upload/files/43139915017.pdf
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/5bef1545a9ca7db8b98dd12969423b05/55866088793.pdf
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/m4jg66osofrrkdoeogh4hj1ns3/21589162586.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160967df47b04f---94393372867.pdf
    • http://calhi1974.com/clients/46234/File/womisew.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/484860e32ccb33f5913958edd25ca0ac/wusewa.pdf
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/7b02c46a453ac58d27add5aef1059104/6360444440.pdf
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/a896c1a8ad9ed35d3b5e0295e7e1bb3a/27940473910.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/160ad90738a6a1---pofavosunojufibitefop.pdf
    • http://tuvanluatdanang.com/upload/ck/files/65651516942.pdf
    • https://nutricount.cz/UserFiles/File/58967380234.pdf
    • http://adamlegal.com/userfiles/file/dewijolazutekapelobosa.pdf
    • http://ototavandosemesi.com/resimler/file/95984492610.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_off0000f0c4.bin
c696d52589fd9d9734f2d090de6bc604618afc7a137e6db6722f7dbc588e2d05
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0C4 19096 bytes
font_01_sfnt_off00012174.bin
a74ed91aa179f0a0153663441fd8a0cff5229af1f567d279171b09847e234f00
pdf-font-stream PDF embedded font (sfnt) at offset 0x12174 10488 bytes
font_02_sfnt_off0001390c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1390C 16792 bytes