Malicious PDF — malware analysis report

Static analysis result for SHA-256 31f0ac2ff1e0dee5…

MALICIOUS

PDF

94.5 KB Created: 2021-09-13 18:03:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4f0b4f025f8cae8da52d74acfa310f75 SHA-1: 35918545d03c12f0aedc267e4de79f5526047466 SHA-256: 31f0ac2ff1e0dee5dea9c7f46ab402bed43d1e5c1a51c5343e6223fba2ee4297
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged by ClamAV as a phishing trojan. Heuristics indicate it functions as a link farm and employs a social engineering lure to trick users into installing browser extensions or updates. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://hsound.ro/images/custom/file/fodudisuvi.pdf In PDF document text
    • http://ingegnasrl.com/userfiles/files/gesopenigig.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210910124959.pdfIn PDF document text
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/noxefafif.pdfIn PDF document text
    • http://snailgame.ru/upload/files/20210902094613.pdfIn PDF document text
    • http://lidaoxc.com/upload/files/1651164087.pdfIn PDF document text
    • https://swift-tw.com/lcc/upload/files/63891838319.pdfIn PDF document text
    • https://vzglavniki.net/data/file/gavulozatoronodusa.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/1f720ec16d1036794a4cd0de30768402/59995334082.pdfIn PDF document text
    • https://e-tta.com/app/webroot/userfiles/files/latut.pdfIn PDF document text
    • https://vannordenvastgoed.nl/userfiles/file/66161632552.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a79fea80e---27197957681.pdfIn PDF document text
    • https://phongkhamtamthan.net/uploadeditor/files/92087166465.pdfIn PDF document text
    • http://cke.hk/userfiles/tefoxapafuzugofodewu.pdfIn PDF document text
    • http://373113.linker.tw/files/zofipazafiwi.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc0de60254---27456560707.pdfIn PDF document text
    • https://servicepapik.ro/files/5168989160.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/rusetuwibofojogamu.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa9b860e78---kanekudekonafewobawon.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/60976961180.pdfIn PDF document text
    • http://osteriailgalloelinnamorata.com/userfiles/files/37239983803.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/85567977004.pdfIn PDF document text
    • http://gamboeng.com/assets/ckfinder/userfiles/files/pibabotuximo.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/75526064204.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109040659476047.pdfIn PDF document text
    • http://sinosteelcode.com/filespath/files/20210904130805.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=can+you+tell+how+often+someone+looks+at+your+instagramPDF 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_off000108f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001210b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1210B 11084 bytes
SHA-256: b53d9e840acba8743237cde4052e5d9dbc38be1c060585bd2f99d0e639e46d3f
font_02_sfnt_off00013acf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ACF 18828 bytes
SHA-256: 47ed7fe83a9e7b5b8969231913787ccfef332cd8699a6934393dce4dde535c60

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