Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1837ff86edb742b…

MALICIOUS

PDF

85.7 KB Created: 2021-09-20 20:49:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1277c9df34072438a73399c1a25885cf SHA-1: 7781d29052123efbdbbc62321dde4d3365573f5d SHA-256: d1837ff86edb742b0bf0cd3e9e1170f1eee62bd1ea1de65deffc4e37d09fa380
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm. The presence of 'utm_term' parameters in some URLs indicates an attempt to track user interactions, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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://wastran.ru/uplcv?utm_term=instagram+2021+apk+download PDF link annotation
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1613924009e863---59378243218.pdfIn PDF document text
    • http://digivideos.net/ckfinder/userfiles/files/25691009029.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/zobosuvizalit.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0be2bc712---59114682179.pdfIn PDF document text
    • http://sdhmladavozice.cz/userfiles/file/vitijun.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/23616950806.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/mipuferuwipevijow.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/81387744923.pdfIn PDF document text
    • https://plasy.com/uploads/file/bejanujononudavot.pdfIn PDF document text
    • http://getdol.com/page_data/file/33130238495.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/36696648099.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/dewezowowunemakijo.pdfIn PDF document text
    • https://digireg.si/upload/38697143028.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/72323124700.pdfIn PDF document text
    • https://doktor-ara.com/userfiles/files/zuwosizukuwij.pdfIn PDF document text
    • http://swissies.lt/ckfinder/userfiles/files/kobinunesigutata.pdfIn PDF document text
    • http://dezmaster.com/userfiles/file/xunebesonogapis.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146faabcf6af---37525577381.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/zudoludabijewixagupo.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/lejirepetemew.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/bazedibezolem.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/47927841259.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/82427485540.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16140ba773b95d---90069323812.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_off0000dc25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f43c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43C 10932 bytes
SHA-256: 00f7e88da1402a69e64160e25e560c2f4a1c8674f56bccd7a0cb56d3db8e7e6f
font_02_sfnt_off00010d76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D76 22356 bytes
SHA-256: f74fc82b563a52e29998ff191566c3a8d80d01a27ff00af261612f9c7baa158d

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