Malicious PDF — malware analysis report

Static analysis result for SHA-256 85a1b1d1b7e68f5a…

MALICIOUS

PDF

75.1 KB Created: 2021-06-26 16:15:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b751aec1f8808dc25f9ffa6ad90f3b4a SHA-1: 82c953a06fcaa17b277db6df7544426f9ceb306b SHA-256: 85a1b1d1b7e68f5ae64fa8eff9dc72d29109cd57cec7efd3515012abd1914f2b
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, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to numerous compromised WordPress upload directories and disposable hosting sites. These links likely serve as redirects to phishing pages or malware download sites, aligning with the characteristics of a malicious document used for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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.focus.mu/wp-content/plugins/super-forms/uploads/php/files/cd8729fbcc706cca46292993789c7bb1/sixixes.pdf In PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609274af121f1---manurif.pdfIn PDF document text
    • http://burfel.ru/upfiles/files/loteberepixusisaxo.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/2f46af5d80d40b7a944e77709bc05664/86946673526.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082485d3abe0---77266003723.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/jewixovurujoleved.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/953efbf1a34b8e0141dcaba082d6204f/40773623142.pdfIn PDF document text
    • http://sneedfamilyct.com/clients/44919/File/gozoziwatozujanepevala.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/62026596494.pdfIn PDF document text
    • http://westleyden72reunion.com/clients/4/46/469dc9162705cbff2d1fbe132f144f37/File/73416846670.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077a1b43bbe4---99259715339.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdef0ad0c77---navimifominituxobawogi.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2dc6ad063---71696010589.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/46a692b4b310fc26255e5637ee75bc75/tedimelifato.pdfIn PDF document text
    • https://erdenet.mn/userfiles/file/tuworoz.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/joxufa.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/18622644139.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/5d77b0a840b604b35443204998a7462f/22877487971.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160830ed5ac221---budozit.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/aj8ann2bt11ap8cduechvjvip0/16244566470.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/ef616529ce8a2d78e48b8438c474c04e/gozekunukuvigezer.pdfIn PDF document text
    • https://elbag.net/wp-content/plugins/super-forms/uploads/php/files/dd08bea9f979b71b7919cebe30a933ac/gopawewa.pdfIn PDF document text
    • http://jejuecotech.com/ckupload/files/vafafefaveziwibiji.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/79030454983.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d01169f1f1f---gufimokumuma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=victimized+meaning+in+englishPDF 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_off0000c05b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC05B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d872.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD872 10628 bytes
SHA-256: 3a817a23b2b395712e5198c44f529920ccf1926232f72a60a076bf938d7b09a7
font_02_sfnt_off0000f065.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF065 17264 bytes
SHA-256: 51b7834cf9c6caea94dec64bd1a84a97dbbd0ef715686fdcce09f23afe84e37e