Malicious PDF — malware analysis report

Static analysis result for SHA-256 91fccd216e531078…

MALICIOUS

PDF

77.8 KB Created: 2021-09-16 02:01:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 43e8d11a4a657d33089105f0c3eb792e SHA-1: 0f94959aa391d38cb0e39ea79b51b99a84272a01 SHA-256: 91fccd216e531078b791e478e56c2dc896ed511a01a5b062b7cb4e33b0315b48
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The file also features a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute further malicious content or phish for information. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.
  • 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.
  • 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://quizai.com/uploads/files/tojubazixug.pdf
    • http://www.northern-japan.com/image/upload/File/vokatunoxavikowe.pdf
    • http://tiyuchangdi.com/upload_files/files/20210904_092852.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613e60cde5aea---barozezodiresijesamisem.pdf
    • http://www.asiacoservice.com/file/files/92488461624.pdf
    • https://fcksa.com/ckfinder/userfiles/files/lexute.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161347036f268a---fopolanufukaxavekotidoso.pdf
    • https://komunalno-vrgorac.hr/files/83058052156.pdf
    • https://lideregitimpaketleri.com/calisma2/files/uploads/90888154601.pdf
    • http://conganbacgiang.vn/app/webroot/uploads/files/4875368735.pdf
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/taruduvuselatur.pdf
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210910125818883071tyhd53.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/rrraoha6l3dn4k8j7i35k0pph6/jojuxetulizilujo.pdf
    • http://ck-buhgalter.ru/userfiles/file/dugekufuv.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/8ce63eeaa20b92b2afa5aed93c82f92e/3567144557.pdf
    • https://bluza-shop.ru/content/File/50544251706.pdf
    • https://laughteronlineuniversity.com/images/upload/files/81603332338.pdf
    • http://gagutp.com/sa_upload/userfiles/file/20210901150317.pdf
    • http://jjc-dev.com/userfiles/file/xorofob.pdf
    • http://baoveantam.info/upload/files/6604563275.pdf
    • http://mptech.vn/ckfinder/userfiles/files/jidudebinapuzelefanedoxe.pdf
    • https://www.cascatai.com.br/ckfinder/userfiles/files/lajimofinunomokufigebopug.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/dfnaeg1mdo9gr6podrsnqm9ce7/83048508519.pdf
    • http://avtrak.ru/ckfinder/userfiles/files/xugumisonezopemufa.pdf
    • https://777mto.info/contents/files/9914827544.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=tomtom+android+apk+download
    • 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_off0000cb97.bin
427b062333a41576fd9c77cd9fefd9d327e94d6e4f6ff0a54e4a6a9a6f1cc787
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB97 10392 bytes
font_01_sfnt_off0000e30d.bin
244e053f9e8de7c0c727c56af67d0ef2613b39bb877013f08c78cd404f868c6d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE30D 17696 bytes
font_02_sfnt_off0001113b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1113B 16792 bytes