Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7a6347e9621acd0…

MALICIOUS

PDF

74.9 KB Created: 2021-09-26 23:35:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 65689a33f86908a898b6c9018d69e480 SHA-1: 129d32ff36394630d7a4b058e6ad7fc0d3ec6fc0 SHA-256: c7a6347e9621acd0cb5ecce17782a6333a2708ceac43c404c0a40212bd8ebec9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://klenderbio.com/upload/files/dobatisufubes.pdf In PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136b757a1ef7---80094366500.pdfIn PDF document text
    • http://boki.hu/editor_up/25818251572.pdfIn PDF document text
    • http://tokyo-sanritsu.com/userfiles/file/pawukipotasogutopusurusur.pdfIn PDF document text
    • https://istanajp.net/contents/files/viwurimitanid.pdfIn PDF document text
    • http://kvrhousing.com/uploads/dunatajuwovaranejinalizej.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161443002b54bd---xomunixipedaladofizof.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/cqb056d2935o2dbkkql6r13ft3/simorujomilebomif.pdfIn PDF document text
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/wodemosejugu.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210913_223354.pdfIn PDF document text
    • https://beeshark.ro/app/webroot/files/userfiles/files/72336163604.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/medabopiwakivaj.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614aff047a397---faruduru.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/vavifa.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dcbf97ca2f---82410841562.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/pukefafowumomokujejexi.pdfIn PDF document text
    • http://snft.ro/media/file/bameja.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161335db19e594---bimukimibut.pdfIn PDF document text
    • http://cascad-trans.ru/files/lixuneramezotazi.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/jamofiganaka.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/mamogejefigogirusi.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/40049569297.pdfIn PDF document text
    • http://insureavisitor.com/userfiles/file/gosititafelokazuxamesuz.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/49413212358.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=effacer+historique+youtube+sur+androidPDF link annotation
    • 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_off0000bef2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEF2 17604 bytes
SHA-256: c583c3bcc976bee58103c006d0efbc13c9e652e5e738be87a2df1472190d33fc
font_01_sfnt_off0000ec12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC12 11008 bytes
SHA-256: d6a7c1bb1d320466c30aa7a2b5c95f3fde33ab7c987302b570e818956df0c195
font_02_sfnt_off00010576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10576 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1