Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5a62b196fc9b279…

MALICIOUS

PDF

82.5 KB Created: 2021-09-20 09:30:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 51ecdc7243ad6dfd759338d6f547cbaa SHA-1: 05f1c83d513a8816e154f307a6bbe5ce0c32c042 SHA-256: b5a62b196fc9b279ded99d9395c08f957e312fbc2ed876aecb94ae4d6d8d62e6
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress uploads or disposable hosting, forming a link farm. This suggests the document is designed to trick users into clicking links that lead to malicious downloads. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 8

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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.barefoothoa.com/webroot/js/ckfinder/userfiles/files/xebafamexakudafekexinu.pdf
    • http://deaprogettazioni.it/userfiles/files/53669528608.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/16148182a38982---67484449281.pdf
    • http://quimicahj.com/admin/userfiles/userfiles/file/nuvukuwiwigomedevazul.pdf
    • http://youngdongtec.com/userfiles/file/xawafabexutujitem.pdf
    • http://autofactory-jin.com/js/upload/files/lulabefu.pdf
    • https://www.rapn.ru/ckfinder/userfiles/files/newulakelejikupezodenixip.pdf
    • http://dulichtantai.com/files/uploaded/files/vakabonar.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/0854265b7791cca984ab04ba44a04f31/xopinepivazilimusapufid.pdf
    • https://www.esicm-old.org/admin/lib/ckfinder/userfiles/files/89212937752.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/0tl4ioeo7023gta13phe91f1mb/mesakifofifojinudafa.pdf
    • http://fc-junajted.com/upload/datoteke/56156554660.pdf
    • http://linkingpeople.info/userfiles/file/xixagafowo.pdf
    • http://hoadondientu-ptp.vn/images/ckeditor/files/11377190626.pdf
    • http://dlzhrjd.com/images/uploadfile/files/90212886959.pdf
    • http://ei-windykacja.pl/upload/file/wexubulazope.pdf
    • https://quizai.com/uploads/files/89926889103.pdf
    • https://www.aicsmindia.org/ckfinder/userfiles/files/dikamumepaviveweretegese.pdf
    • http://budapesticukraszdak.hu/userfiles/files/wijivo.pdf
    • https://dewalt-naradi.cz/media/upload/editor/file/gudixowevukajodof.pdf
    • https://curtain.jinware.com/upload/files/lipunulonunujomuwojuwegu.pdf
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/dotasowegegugobuwazafufu.pdf
    • http://oris-am.com/editor_up/sojetidubul.pdf
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kidifivifitiradusav.pdf
    • http://maysoi.com/hinhanh_fckeditor/file/nelenurabupefazizexedav.pdf
    • https://bocion.com/ckfinder/userfiles/files/6095316599.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=the+dark+knight+rises+android+game+requirements
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd58.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD58 16792 bytes
font_01_sfnt_off0000f56f.bin
c542b519a28180be856349918ca75299152131d5a732fb2c9be607958787c63e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF56F 10952 bytes
font_02_sfnt_off00010e22.bin
57f998f56d272e101a3a4fc68542d80c7a93eebc1b47ebef2d3c51af23f444c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E22 17576 bytes