Malicious PDF — malware analysis report

Static analysis result for SHA-256 e0feaa9765ba7642…

MALICIOUS

PDF

76.0 KB Created: 2021-09-24 13:19:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f78d53da8d018234f97c80ee9bc110f SHA-1: cfdaaa942ba2e85eb269c63a16ccaa6985098a39 SHA-256: e0feaa9765ba7642772f9e99c89243b36586ea9f43135557a9b6e7a1389c8b1d
96 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, and multiple heuristics identify the PDF as a link farm. The links point to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious sites. The document body is unreadable, but the presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://bon-mar.com/fck_user_files/file/ruzadetetijobipor.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba253be070---fupedanumata.pdf
    • http://rszm88.com/upfolder/e/files/20210905075104.pdf
    • http://tubelessons.net/cms_images/file/dodabulukeluwezaduvuf.pdf
    • http://ssss-sangam.com/userfiles/file/vatasoxuxatazemuxoravas.pdf
    • https://aqua2go.pl/galeria/file/44715718077.pdf
    • https://helicopterleasingservices.com/userfiles/files/13424459064.pdf
    • https://advik.net/userfiles/file/xuvewunawanuk.pdf
    • http://studiotipaldo.com/userfiles/files/mevojejeseteb.pdf
    • http://1666-3668.com/attach/userfiles/file/24688660592.pdf
    • http://7m-shop.com/userfiles/file/wesesoduwepu.pdf
    • https://cvssteelex.com/ckfinder/userfiles/files/rexifumazasa.pdf
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/34316984025.pdf
    • http://xn----7sbicwad4afgcgd5aph7d5e.xn--p1ai/ckfinder/userfiles/files/mewivip.pdf
    • http://pnalog.ru/images/file/84249550851.pdf
    • http://elmawadah.com/userfiles/file/81844177050.pdf
    • http://manavpublicschool.org/manav/userfiles/file/30691215092.pdf
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16138c21639b44---jujopilesawoluvudad.pdf
    • http://e-photo.lv/ckfinder/userfiles/files/86705996513.pdf
    • http://mopron.ru/upload/files/36526427096.pdf
    • http://sinsg.com/files/fckeditor/file/45237388360.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613595d5cb7a8---bedekikinapawe.pdf
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/kofatoxeliwugi.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/6e64282e6750577379c420657052e046/sifobafikaxagogu.pdf
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614894c0d1b7b---69848003010.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=dead+man%27s+hand+rules+pdf
    • 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_off0000c11e.bin
2f0c083fc1873c414c9db9f01d3b5ce897979b213fe5705720ae27f72c4cde3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xC11E 10588 bytes
font_01_sfnt_off0000d90e.bin
65ebd89e8c472c14b1cfb3af9b3af68747508ad0079bee5fbc68f3d28972fa74
pdf-font-stream PDF embedded font (sfnt) at offset 0xD90E 18720 bytes
font_02_sfnt_off000109dc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109DC 16792 bytes