Malicious PDF — malware analysis report

Static analysis result for SHA-256 1606bc01d7e76455…

MALICIOUS

PDF

108.0 KB Created: 2021-08-07 13:17:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 81c3781acecc583628abf1cbe2f133e9 SHA-1: 9f860da121c1a0c628bf98af83e86786047170fb SHA-256: 1606bc01d7e76455bd3564daee9da1c9b32e3d3b838d21738e47dd13a2c8f8a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to compromised websites or link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body is unreadable, but the heuristic firings clearly point to a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://cokhiminhhien.com/media/ftp/file/vegipedejarafido.pdf In PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/35831649956.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/dirajomaxibisad.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160811c0e3deb3---ziwudiva.pdfIn PDF document text
    • http://cloverdiamond.com/file/42732379626.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc330dc429---4646547637.pdfIn PDF document text
    • http://sity-luxe.ru/userfiles/file/vojujifufo.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/117332050cfc8d068e910daca60389d4/43587506385.pdfIn PDF document text
    • http://blsfamilyreunion.com/clients/1/11/11e20eb1c47c3498ff3e66fc1941d138/File/totepeb.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/pedububasem.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/13684234938.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/kokuparapazenubegogokab.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/8f91ab472acb01957956d7a22c114cf1/kogejulitejo.pdfIn PDF document text
    • https://ewt.cz/res/file/nagenuwijenokur.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/24371253073.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/3nljmuqm21fjv1nlef1lme4fht/damigeveg.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021070706314847.pdfIn PDF document text
    • http://hcvitamin.com/webroot/img/files/gikazod.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dd7218719b3---32655050371.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b1286eb6dc---falizefusulawareroruso.pdfIn PDF document text
    • https://flyags.com/editorResources/file///54070832300.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160734b156cf1e---zesenoje.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/44490019503.pdfIn PDF document text
    • https://chupwo.com/editor_upload/file/49672668377.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=what+are+abiotic+factors+in+a+kelp+forestPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000141b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141B2 18112 bytes
SHA-256: 5fb75dffb64dbaad8737d2deec4883287c93a979ee5e784fc8bcd592bcb8ff4a
font_01_sfnt_off000170bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x170BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000188d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x188D6 10804 bytes
SHA-256: 9f5b3900c655ac7f614dfd75f6c348fbf8935c0e77d9665b5b7c521903fe691a