Malicious PDF — malware analysis report

Static analysis result for SHA-256 816befe6b6ed58f8…

MALICIOUS

PDF

102.1 KB Created: 2021-09-18 22:53:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1b726e7418d9c30c1c4c521dcd0f7150 SHA-1: 4acd789029c87be0e1b95beb54c9cd337e18262e SHA-256: 816befe6b6ed58f8cd3bcff6bd4033e912ed1df2b80d25e61c34f6ef2865f272
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=moto+g6+pixel+experience PDF link annotation
    • http://on-video.com/movies/movie_data/file/tazekalerej.pdfIn PDF document text
    • http://esejsc.com/upload/files/baderugibulum.pdfIn PDF document text
    • https://imad0c0.com/js/ckfinder/userfiles/files/5767748425.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/13854328169.pdfIn PDF document text
    • http://rooptex.com/uploads/sidotenofilopereb.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4b290ace2---50376387512.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/cv29q1rve66covfne37k4cbpba/fojizatakibesasigob.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/28243836020.pdfIn PDF document text
    • http://darangyi.com/userData/board/file/vaguvajupire.pdfIn PDF document text
    • http://davidhammerstein.org/ckfinder/userfiles/files/49656729005.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/31959297767.pdfIn PDF document text
    • https://equimat-cheval.fr/file/jolenidabilanemujop.pdfIn PDF document text
    • http://moscowprice.com/content/xuploadimages/file/kulugipalijevoxex.pdfIn PDF document text
    • http://shsuorui.com/uploadfiles/fckeditor/20210910/file/16312999643759.pdfIn PDF document text
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/27673000168.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/perawug.pdfIn PDF document text
    • https://griby.biz/ckfinder/userfiles/files/80496484571.pdfIn PDF document text
    • http://chanakol.com/ckfinder/userfiles/files/85630386623.pdfIn PDF document text
    • http://mp-journal.com/media/file/77086784561.pdfIn PDF document text
    • https://technoarc.net/userfiles/file/91668989091.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/razizugesa.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1613e49418d565---dusitatorifove.pdfIn 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://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_off0001291b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1291B 10480 bytes
SHA-256: 8d7765acb6939c428a7f7e839095d3961dcbd5126a18e7c62139fd60452f915d
font_01_sfnt_off00014110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14110 18868 bytes
SHA-256: 38ca6cdd27980aaef2a52c67a985b4a8fdbca4b9a8734f80102e1c01ff691581
font_02_sfnt_off0001728d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1728D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1