Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d8fc6b712ae5851…

MALICIOUS

PDF

69.0 KB Created: 2021-09-25 10:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a70a02d9e0f629470bf544fc7a2f546d SHA-1: d7612630299dc183314ae3d4ecdbf218091038e2 SHA-256: 5d8fc6b712ae58515808c741650378db90eaada212b2da9365ab317949a719d0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the document is structured to redirect users to potentially harmful content. No scripts were extracted, but the overall structure points to a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 https://archism.ru/uplcv?utm_term=kako+da+skinem+pesmu+sa+youtuba+na+android
    • http://unitez.net/images/newtech/files/64704893450.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e3f953f5f---lezolizunidikupodemo.pdf
    • https://nulifeus.com/~nulife/userfiles/file/veromaxegekovefopi.pdf
    • http://newcityhk.com/userfiles/nukuzolik.pdf
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/81198272465.pdf
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/d92a10166b1f91f79a120c25b2ecebc0/xezofotutusafi.pdf
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/wasabiwurudozagalalam.pdf
    • http://balbu.eu/uploads/news/file/duvuzuwafu.pdf
    • https://zbmbudomont.pl/userfiles/file/88536671327.pdf
    • http://hoya-system.com/uploads/files/202109171035348487.pdf
    • https://aquatrustfina.com/userfiles/file/gujiki.pdf
    • https://mariellatriolo.it/public/file/buredokowivijelawugupino.pdf
    • http://tnetimes.kr/upload/file///sawirukaboj.pdf
    • http://bjxbw.cn/userfiles/file/ravizo.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/3912eacb81c3a588e5ad350d6dc3e4c1/54245235556.pdf
    • https://priscar.com/documents/files/27212089081.pdf
    • http://belgium-ex.com/images/blog/file/rokononafoxurok.pdf
    • http://greenegiving.aboutgiving.net/sites/default/files/editor/file/61563915648.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148f0f5c0e8e---73578673361.pdf
    • https://sbmhavacilik.com/userfiles/file/pinovakinedilavakixiretag.pdf
    • https://interstudy.net/userfiles/file/77779080208.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_off0000ad8b.bin
48011ad2b5cf370f06a178787804c302a9ddf1b20c4b2c7007626c9788c52a72
pdf-font-stream PDF embedded font (sfnt) at offset 0xAD8B 10944 bytes
font_01_sfnt_off0000c6b1.bin
401334dbe46acfb89a2011421a6fab65975423f37f37342d39b65c5bf5215c66
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6B1 15660 bytes
font_02_sfnt_off0000ee0a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0A 16792 bytes