Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b8e3c416e09b6a3…

MALICIOUS

PDF

89.9 KB Created: 2021-05-12 14:02:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 0d4b7c5ce61016976ffe2f1b74626a2b SHA-1: 6a197f1b859e39228846841172785166de14639c SHA-256: 7b8e3c416e09b6a327e9de92465be4467ce33ed019bec903157e972360a4dfc6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs that point to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the extensive use of external links is a primary indicator of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=music+to+apple+watch+5 PDF link annotation
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/8c457a2b3c65454ab9014a9c74a719cc/wofetavevipuduz.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/48523432213.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/10c1c618a2e5190dc5042055c3da64ef/46700354328.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1608515c99a456---50743824217.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/2e1tpoqrkdb9fmif75gmfera68/23594978542.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/98544183604.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/96293485930.pdfIn PDF document text
    • https://betenrealestate.com/sites/default/files/file/92268609428.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160922924e9bc3---dinizoxetarolewup.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16079dc13e6f0f---79995933692.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/8df73c51acdebb64da57a571f043a586/fuguwejup.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608515ee8c441---65373792204.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/56f4b8e09e735b7ee15db8a6618281d1/53713954541.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1607d42813c031---65747633887.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d659891f38---danokodatepezur.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/tjnu935pdtcbmo9b4q3gds1ivl/51994959315.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012066.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12066 5148 bytes
SHA-256: 79aafea3c464abb7c28d7c2b47b5d1dc6ac524df42d22e1ad6999838be7a5d4f
font_01_sfnt_off0001320b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1320B 11584 bytes
SHA-256: 2c12391fa8a492423ea017be460edd1434d0449c9ed821a68d4ad14cf6f17704