Malicious PDF — malware analysis report

Static analysis result for SHA-256 44a25a56910f5dc0…

MALICIOUS

PDF

77.3 KB Created: 2021-07-02 20:36:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d6fdb72bb4814db4234da3a28045c1c0 SHA-1: 5be7868ec2715cfec460b40920d63c10c15ac243 SHA-256: 44a25a56910f5dc0ff1c8b09f67871a9e43fcb3e1eb2fc15ce975fbb5293e8da
156 Risk Score

Malware Insights

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

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. These links likely serve as a redirection mechanism to deliver malicious payloads or phishing content to unsuspecting users. The presence of these compromised domains suggests an attempt to leverage legitimate but compromised infrastructure for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/677da440c924cbbe5539476ba9979d11/kesolon.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607463cc5d3de---38999649130.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160902e037eef9---kinesedinivalubaromoduraw.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/17j0oo9v1bcf5pnq8fibt8nn0d/xeraserefepinelewapuwaso.pdf
    • http://homenet-spb.ru/userfiles/file/49491112698.pdf
    • https://e-fasteners.eu/media/file/87464345273.pdf
    • http://gfhs1978reunion.com/clients/56625/File/3313706976.pdf
    • https://global-product.org/CKEdit/upload/files/24298449794.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/i8f95rbejo4pns125hrd2735l6/64869506987.pdf
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/899c858f292e6831eb7baabf07807bf1/farififopezunexononixanot.pdf
    • http://chistogood.ru/admin/ckfinder/userfiles/files/18470607698.pdf
    • http://orderleesushi.com/uploads/files/lixovukuz.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098d92dd5ed0---17666227994.pdf
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/8ok8nmmqphcubmr67dmtbuo59p/povojaso.pdf
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/m4udfuhkjro129k5ubcg0q15t3/54211256733.pdf
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/2dad68489c6191e32bc5ad0516379e9a/10448142069.pdf
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/ea8c68414fae21f98d08911fc7b2b7bc/11655968396.pdf
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088f0fed4004---jaxufa.pdf
    • http://nirmalapublicschoolerumely.com/userfiles/file/tulizoxek.pdf
    • http://apsencollege.org/test/fckeditor/file/52805727022.pdf
    • http://andlupa.com/userfiles/file/lusirozunekiwozizemamim.pdf
    • http://strahovka66.ru/userfiles/file/raned.pdf
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/3aa9ff32e9004959f46990f637983d5d/18462406981.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a79c8e8b2c8---vorupov.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=augie+rios+now
    • 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_off0000c9ad.bin
8d2bb40ceb489c6d2d94bc20fbd4601a28c092f31b9ba80469022866b1887aad
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AD 10144 bytes
font_01_sfnt_off0000e085.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE085 16792 bytes
font_02_sfnt_off0000f897.bin
20a0ae4a9f5b3bdafea569c1ab3cb925fcea8b1c32dc21618342c4fbdcbaaac8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF897 17812 bytes