Malicious PDF — malware analysis report

Static analysis result for SHA-256 420eb84403f5b895…

MALICIOUS

PDF

85.1 KB Created: 2021-09-20 01:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a2a88b8f0a77157c4c50d819d852f2e3 SHA-1: 05bf1e5413c800fb408faf0253706d11034dc2e6 SHA-256: 420eb84403f5b89596057bf43f8807977ca795dbd514fcb81e08dec5f82d3c80
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on compromised CMS upload directories or are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these external links. The presence of embedded JavaScript suggests an attempt to execute malicious code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://nomylo.ru/uplcv?utm_term=instagram+reels+download+hd
    • http://theclelandgroup.com/img/upload/file/92115155470.pdf
    • http://kryotherapie.net/neu/userfiles/file/222451185.pdf
    • http://tvoirostov.ru/ckfinder/userfiles/files/84022803083.pdf
    • http://emachn.com/data/attachment/file/62621717185.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/55ae21113d1ecc5ba450ad277f14a808/71703005554.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/um3bovskfgcfh85ltefd5hd3rg/36325842790.pdf
    • https://curtain.jinware.com/upload/files/duzagetenoxadoke.pdf
    • http://hyundaiokla.com/uploads/files/kaledasadar.pdf
    • http://tubelessons.net/cms_images/file/4386174018.pdf
    • https://www.idd.no/ckfinder/userfiles/files/bakalegetivuwugamopobijub.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16140edc158a7e---12833015191.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161433e0517e1c---9504142729.pdf
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147a60752197---jajogarabixomam.pdf
    • http://phonphangschool.com/upload/files/62402748188.pdf
    • http://www.artefuoricentro.it/js/lib/ckfinder/userfiles/files/88772683969.pdf
    • https://www.naabelectric.com/userfiles/files/58042340634.pdf
    • https://coil.hk/upload/files/8964212588.pdf
    • http://rivebistro.net/ckfinder/userfiles/files/dedanalobetefeler.pdf
    • https://almuhja.net/ckfinder/userfiles/files/tobiziza.pdf
    • https://stradatextiles.com/upload/ckfinder/files/golefuzujopuvimezazas.pdf
    • http://blessingsngo.in/userfiles/files/vizogivowenizir.pdf
    • http://ky-auto.com/uploadfile/files/67669843072.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_off0000e8f8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F8 16792 bytes
font_01_sfnt_off0001010a.bin
a0eceeaae41b94a51bdaff6c65347610e9dec50ab5d81ecc55da663794d7b833
pdf-font-stream PDF embedded font (sfnt) at offset 0x1010A 17496 bytes
font_02_sfnt_off00012e87.bin
3cbcbc409760df6cfa257f4b5fe581f7377e2088badcdfabb2b9a1003ef61e93
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E87 10640 bytes