Malicious PDF — malware analysis report

Static analysis result for SHA-256 c851ef16e2b4136c…

MALICIOUS

PDF

81.5 KB Created: 2021-09-21 22:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 89ed6a27bf03e0ce5b8e83c972edccb2 SHA-1: 79dd67a624e6de087e9041712c809a48c2e837ee SHA-256: c851ef16e2b4136ccf30ec38b497295d0720c120aad3e31a6476054c9e8b4b4f
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The presence of numerous external URIs, many hosted on compromised or disposable domains, indicates a link farm designed to redirect users. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic specifically points to this tactic, suggesting the document's purpose is to drive traffic to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ajej.pretty-match.com/upload/files/xutolefasegaz.pdf In PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/cba316c9cf31ba971294e6f7ce91199c/16106986768.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/23100081773.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc5428fa3c---nunuxawa.pdfIn PDF document text
    • http://aczelzalog.hu/tmp/nedodegokevagufum.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/11832937148.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/vri0tbepe3hktcv121mrgf7hv0/75255352879.pdfIn PDF document text
    • http://land89.com/ckupload/files/27598019076.pdfIn PDF document text
    • http://tbm-mova.by/images_from_html_editor/file/17543763450.pdfIn PDF document text
    • https://martas.vodrsport.cz/uploads/files/40899162927.pdfIn PDF document text
    • http://csc-020.com/userfiles/file/20210915160752_a3kmae.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/nozapejaxitenaduxoxa.pdfIn PDF document text
    • http://frutapac.es/ckfinder/userfiles/files/22384889456.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/88389820690.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/tajizew.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/2144887195.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/jorazizokozitazemezav.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/pegukezago.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/xivotigarawoge.pdfIn PDF document text
    • https://healthlantern.com/ckeditor/ckfinder/userfiles/files/zufosovitumi.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16140eef770749---wijipodotanopidu.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/24103082500.pdfIn PDF document text
    • http://uteambio.com/upload/files/pozutasipoleruzana.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/65934566549.pdfIn PDF document text
    • http://jpsacademy.com/slbdavbatala/userfiles/file/25886870771.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=mp4+mp3+converter+free+download+onlinePDF 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_off0000d8a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0BD 11008 bytes
SHA-256: 85c4bf900930f29cd39a603a09be0aebc5d8a41e012227abf88d52c94d1e2052
font_02_sfnt_off00010a65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A65 17416 bytes
SHA-256: 9534dddbb2f8565e0eb37920cf6ad06a937d36bbb5afbef85300170820d0e789