Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa9af0fd613cdff1…

MALICIOUS

PDF

89.1 KB Created: 2021-09-23 17:25:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c5347bece64957664e58a8e1cb82be2e SHA-1: 0ba65e2b9d1954bc44f67380bb08fb7aba2ac93f SHA-256: aa9af0fd613cdff17ac60797877d7481e8253e74e10076df019a6821c85b161b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs pointing to a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ksdc.in/userfiles/file/zitenegakebumumaw.pdf In PDF document text
    • http://www.lovebliss.tw/UserFiles/files/33608148857.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/xanerelufumezafekukageni.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/32909763943.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/25097515506.pdfIn PDF document text
    • https://booking-news.hkdnracing.com/webroot/editor-uploads/files/6599309377.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/nadije.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/87114772136.pdfIn PDF document text
    • http://7sate.com/filespath/files/20210923032147.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202191892499730.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/28816743763.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/67816578289.pdfIn PDF document text
    • https://meganimal.pt/site/upload/file/sibanesupepeve.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/sapusixutukolawome.pdfIn PDF document text
    • http://bellamy.tw/uploads/files/202109050228156384.pdfIn PDF document text
    • http://355353.ru/userfiles/file/xijejikoxukufinadis.pdfIn PDF document text
    • http://birdwatching.sk/media/file/bewoxezafujovezotix.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a83aa4fa94---50249770365.pdfIn PDF document text
    • http://songhakbbq.com/uploads/files/pikonudewimowudigipojewul.pdfIn PDF document text
    • http://salt17.com/userfiles/files/30374176212.pdfIn PDF document text
    • https://venus-forever.com/image/files/vukanaxaderivukexopiku.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/93806641045.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/joxovugabiradagubamanaxer.pdfIn PDF document text
    • https://www.zochrot.org/ckfinder/userfiles/files/27653031913.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=cara+menghubungkan+internet+pc+ke+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_off0000f351.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF351 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B68 11108 bytes
SHA-256: 7f5283f6554a307e511ffadc008f78af3aaa2246e12730f4e5ee49c726e73158
font_02_sfnt_off000124ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124AE 19228 bytes
SHA-256: 15d142d14bfe5575ecda44eba3533f6b4958330db36a9b2af0782318bf1bc508