Malicious PDF — malware analysis report

Static analysis result for SHA-256 78997069c7ff21db…

MALICIOUS

PDF

82.3 KB Created: 2021-08-15 19:44:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c957da653c528cfbd9b7f42cce8ccd2f SHA-1: 211a1177cd39d331b44041abd3fac30e7a28fccf SHA-256: 78997069c7ff21dbf561cf8d79d3f37e05bd76f15726b6c9ddd18ad7f1da8e01
164 Risk Score

Malware Insights

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

The PDF was identified as malicious by a machine learning classifier and ClamAV, with high confidence. Several heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites. The presence of external URIs and link farm indicators suggests an attempt to manipulate search engine results or redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 7

  • 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.
  • 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://queure.ru/uplcv?utm_term=math+coloring+worksheets+for+1st+grade
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2c81c0200---mogasinan.pdf
    • http://korean-school.hu/hangul/userfiles/file/wumepokakalaxarab.pdf
    • http://wsp.pl/userfiles/file/bemezuneresaje.pdf
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607ca653285d5---vufunewubolodetuzalisava.pdf
    • https://bak.vn/upload/files/44465560146.pdf
    • http://cathugo.de/res/wysiwyg/file/vizelutenigivolige.pdf
    • https://accuratesearch.com/userfiles/file/damiletasokoxevidovor.pdf
    • https://moveo-sport.pl/userfiles/file/61303562843.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4b9b16711---tejesavajanusas.pdf
    • http://tsradviseurs.nl/mailing/images/photo/file/ragiseguwozojewalo.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/3c6eda2c37747b9cbbada4b80dfd2b29/93785914772.pdf
    • http://monterroso-construpuntos.com/campannas/file/jusuzexefupuzenudiwuvove.pdf
    • http://langeline.com/ckeditor/upload/files/24218206008.pdf
    • http://adirondackseafood.com/ckfinder/userfiles/files/28555746137.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106146d258cb---90890053114.pdf
    • https://faresaldabbous.com/uploads/files/13769236262.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160be62e74cb7e---82347604974.pdf
    • http://haiphongcontest.com/images/files/diloperadide.pdf
    • http://angelojrobles.com/admin_initial_test/userfiles/file/45926069176.pdf
    • http://obasekiestates.com/UserFiles/file/mopajujotemipavujokidar.pdf
    • https://alixdemassy.fr/userfiles/file/15415586438.pdf
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606c972d95635---46108756243.pdf
    • http://gryfarmerskie.pl/pliki_wyswig/files/79074312594.pdf
    • https://alianzatours.com/imagenes/file/53991339734.pdf
    • https://myphi.biz/nbloom/fckuploads/file/ridemisif.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16075236e74a4b---naduzel.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_off0000db40.bin
d44962a68906cb70ba2b637cb3522da0250ae2f0c50153129db58e3c21a82a12
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB40 16864 bytes
font_01_sfnt_off00010771.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10771 16792 bytes
font_02_sfnt_off00011f88.bin
b3f67cb4c41acd3803260a1d0b4340aa6bea887c24c3d220c5c89c3d32ce6785
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F88 10980 bytes