Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a0b5a18bedf5938…

MALICIOUS

PDF

84.4 KB Created: 2021-06-27 02:14:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 10f2702cd290a3f4a0f9dd1daeb195c2 SHA-1: f6b0058af5090c4976edd87986ded28f3aa47284 SHA-256: 6a0b5a18bedf59388b9e2157c21243b4aabef800da27abf69879fbd7fdbd0c52
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, likely to lure users into clicking malicious links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://krisoc.ru/uplcv?utm_term=personal+word+wall+pdf
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/232d0a91e10e3220f5812f7acfbece32/54305035035.pdf
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/bbu9dvh4st98mgo1ldsmca79p0/90101776810.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/0o1gessl81eccclvqhpotqslde/pokirixixufilipaf.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16073f5634f5df---foxedaladamu.pdf
    • http://www.bash.cl/media/file/31442583834.pdf
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d24840d8b9---10422542666.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b7cf29e278---tatotolipezamujokofudogaj.pdf
    • http://conblocmanado.com/pics/file/nadusedu.pdf
    • http://seamacros.com/upload/file/gonokinaxugizatomekupo.pdf
    • https://preprodpcb.com/userfiles/files/34580824723.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/b373d12dabc27db29eef13bfd9a3b1ff/liwuzunol.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607cfa87cec12---nenafalitikup.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/43baed20cb9e86fb6f64fbb87643849b/93187462116.pdf
    • http://elmbbq.com/uploads/files/rejomolabuvozirajiv.pdf
    • http://canvangdientu.com/images/file/wotitapigumijavil.pdf
    • https://teenvolunteerhouston.org/wp-content/plugins/super-forms/uploads/php/files/e04e93a1ab46249ad141faea649ce82f/37466767378.pdf
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a638516422---81788757412.pdf
    • http://emailreceptionist.net/userfiles/file/zirat.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/8f2c1b1c03194f26e2773c9e69b0d643/rofogaginunodolupa.pdf
    • https://rocksoliddesigns.biz/userfiles/file/nusezijotajugokifowomunal.pdf
    • http://onishi-kyosendo.jp/archive/mibixunef.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160765119bf81a---31344644939.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_off0000e62a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE62A 16792 bytes
font_01_sfnt_off0000fe41.bin
b4d5ef91bccdf0bbab66c58c73fad6231695c8fd7e192e1bed9e4578d4d9a802
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE41 10388 bytes
font_02_sfnt_off000115f4.bin
37ba2ffc7e81f87352b4632026430237f5aacb03d1d9ca1aa68cce1abaf58a06
pdf-font-stream PDF embedded font (sfnt) at offset 0x115F4 17780 bytes