Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef75b12faf17dd6d…

MALICIOUS

PDF

71.4 KB Created: 2021-09-29 02:43:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6f9aa357c1c96ff3babd78496c41696f SHA-1: dba1283be67fcfb7f1af05c149956ec290732a43 SHA-256: ef75b12faf17dd6d6f9db59d82934a70715d7f86020f150bbb663d39aacc5c89
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, some of which are hosted on compromised CMS uploads or disposable domains. The presence of numerous embedded URLs, many pointing to potentially malicious content, supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://slsnn.ru/content/files/28862441897.pdf In PDF document text
    • https://alkoplast.rs/files/bipolabigivuliriva.pdfIn PDF document text
    • https://charming-dc.com/uploads/files/202109092009135206.pdfIn PDF document text
    • http://micruts.org/userfiles/file/51651977190.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/a1hqq9jg1luj0o745dqoutkrg0/gizokamowewavi.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/r4oss2kkprhg4e4ojdf61iph72/ropijevitopesiguzutifof.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/dafogikovowunixujune.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/babuz.pdfIn PDF document text
    • https://mycocoa.org/images/upload/files/56839939582.pdfIn PDF document text
    • https://webdatedepot.com/userfiles/file/safipazogumikapudanoxoped.pdfIn PDF document text
    • http://smsgurugram.com/miet/assets/files/60234942564.pdfIn PDF document text
    • http://enricobarraco.com/files/zefebufapesuxapoveroma.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161321513d7679---84695691913.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/51478478138.pdfIn PDF document text
    • https://flavio-tonon.it/public/file/48914890245.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/96896589727.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/15334984884.pdfIn PDF document text
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/jezelo.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/54986714861.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/17789160504.pdfIn PDF document text
    • http://exhibitionchannel.com/upload/95636804712.pdfIn PDF document text
    • http://arabic.cz/ckfinder/userfiles/files/tukugarebuliwipinezanu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=signalr+java+client+examplePDF 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_off0000b1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1FB 17380 bytes
SHA-256: 811d28690d3bb9f42de5f818faa33a43aecc58ca4c8983aa404b8de6780c0be7
font_01_sfnt_off0000dd78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD78 10800 bytes
SHA-256: 34e9206b207120b956975847ef0d5ad06c19d828d6a06b66f161d598be2d0ee2
font_02_sfnt_off0000f65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1