Malicious PDF — malware analysis report

Static analysis result for SHA-256 850bf128b2ff3d94…

MALICIOUS

PDF

68.8 KB Created: 2021-09-15 17:01:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: e48c8c8fb4b1b4672f17d4947c2c69df SHA-1: 74ef51c6a52a28ee192c4cdc33b42fd251c150e7 SHA-256: 850bf128b2ff3d9406842448e74bc6c2b899889aa9e34b5e9507fb987293ff68
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many of which are hosted on compromised or disposable domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm on potentially untrusted hosting. The embedded JavaScript likely facilitates the redirection to these malicious URLs, aiming to deceive users into visiting them. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

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://smidgel.ru/uplcv?utm_term=how+to+update+my+emojis+on+android PDF link annotation
    • http://sunil.kr/uploadfile/fckeditor/file/vovitutoxurusofizo.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/pebizefeleriw.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613591dbb8ecd---kinedimunozowedu.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/83680669580.pdfIn PDF document text
    • http://letdentalab.com/img/files/38724042785.pdfIn PDF document text
    • http://chrisnoblelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dekimewulatesexu.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/womelurexurawuwuvo.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/wolutorututanu.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/61444283574.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/52881756761318166dba92.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/poxuwasejixirivavaxatana.pdfIn PDF document text
    • http://akconta.com/uploads/files/jedewebugepika.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/xifoni.pdfIn PDF document text
    • https://snpwachq.com/files/js/ckfinder/userfiles/files/31905047527.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/falixamowalum.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/vupelizixibaf.pdfIn PDF document text
    • http://efuturesthai.com/uploads/file/devutuw.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613402ab4b5d8---17567514968.pdfIn PDF document text
    • https://marcvandewiele.com/userfiles/file/42402779511.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/59285a23c6921cf7db3ac1604d39875a/laloje.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/161409259842a1---25496140892.pdfIn PDF document text
    • 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_off0000af85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF85 14788 bytes
SHA-256: b1f55e6067d6ca35a10dc5fb9ce5c6590012ca08d7e57b3766b4d459e789458a
font_01_sfnt_off0000d446.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD446 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5D 10928 bytes
SHA-256: 48a8a29a9098786a0739c16cadb93538aa6953652229f32146c41c60dc7cf70c

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