Malicious PDF — malware analysis report

Static analysis result for SHA-256 08a99fb0f4f9e97d…

MALICIOUS

PDF

79.6 KB Created: 2021-09-12 21:45:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 359ac8e68e1b2d55da71cf5b61f21463 SHA-1: b116d62bcb53ae37f23243fd33b1608f79f1a444 SHA-256: 08a99fb0f4f9e97dc65eaba347d913378b3d29c8d86935541f75b5228ce68467
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to other PDF files, likely for SEO manipulation or to distribute further malware. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://iphonedown.com/ckfinder/userfiles/files/99035385462.pdf In PDF document text
    • http://hmconcretemixingplant.ru/d/files/belakujazuf.pdfIn PDF document text
    • https://suprizpin.com/calisma2/files/uploads/30152181859.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/627a2807a8f8cb39b86f290cdaf1eb50/6764588407.pdfIn PDF document text
    • https://gimenezricarte-deltabogados.com/ckfinder/userfiles/files/pudamulobusitifut.pdfIn PDF document text
    • http://dorapeyzaj.com/userfiles/file/54983933521.pdfIn PDF document text
    • http://patrickstaxi.fr/userfiles/file/silufu.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/relomijupixegalibokuxomuv.pdfIn PDF document text
    • http://malerbetrieb-malanders.de/Webseite/pics/fotos/1/file/pefagexozilapunabilijive.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/89469198565.pdfIn PDF document text
    • https://huanghecables.com/d/files/bixinebofawed.pdfIn PDF document text
    • http://sjccgy.com/userfiles/file/61569851355.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/92927488158.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/040311438581.pdfIn PDF document text
    • https://nyig.com/files/file/43781789480.pdfIn PDF document text
    • http://polishingmarblefloor.it/userfiles/files/jufovive.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/31977481956.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads/files/202109051217548513.pdfIn PDF document text
    • http://intertexmedical.com/userfiles/files/webudujakaganetizated.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/jemakutawodipajikojitaku.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1613d11bc0face---2861512897.pdfIn PDF document text
    • http://kcntanduc.vn/img_duhoc/files/lirexogeredilafirunuvore.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/57597546522.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ket+speaking+practice+pdfPDF 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_off0000d1a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A9 10712 bytes
SHA-256: bbf5e820375a56d18f6e298c451808307fb953fa519559481ac53916e1eeb228
font_01_sfnt_off0000ea3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3A 17920 bytes
SHA-256: c0f8c4ab8866f052f7d76bb5e1744b68a58101ec21b815ad0fe02aa503361e32
font_02_sfnt_off000118b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1