Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a8cf3296ffd2c9…

MALICIOUS

PDF

82.6 KB Created: 2021-09-09 04:19:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9f3591756883922492473c2d8162910d SHA-1: 6e3e0f84f031b80e13412bfdd6fe158769d5f9c9 SHA-256: b3a8cf3296ffd2c99bcd183dc087d933eb20c475a0464968086221d4ac00bf7d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links, likely directing users to potentially harmful websites. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210902041916.pdf In PDF document text
    • http://stickers-moins-cher.com/userfiles/stickers-moins-cher.com/file/bidegukemagusata.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/buwosukupefafeb.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395dc600877---16268056231.pdfIn PDF document text
    • http://studiorestagno.eu/userfiles/files/61019897572.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/kuxesimum.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/88356818415.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/jewekorisemamefuj.pdfIn PDF document text
    • http://hoanggiaphatland.com/uploads/image/files/82156637682.pdfIn PDF document text
    • http://aibasavar.edu.bd/app/webroot/ckfinder/userfiles/files/58067987241.pdfIn PDF document text
    • http://sanraimundo.cl/dyn/uploads/file/tazenozokaja.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334a6ef18d4---73975687597.pdfIn PDF document text
    • http://on-video.com/movies/movie_data/file/nuxiremotolasalogibiroro.pdfIn PDF document text
    • http://redeyeldn.com/userfiles/file/37646158652.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210905125639.pdfIn PDF document text
    • https://sweetburden.com/upload/users/files/kobesovovejujonuvoseso.pdfIn PDF document text
    • http://achwvs.love-mrt.com/upload/files/tezale.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/97566433666.pdfIn PDF document text
    • https://verticala.ro/images/userfiles/13780468609.pdfIn PDF document text
    • https://xn----7sbbg1ddpkdc.xn--j1amh/uploads/files/kewakejalewera.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/40903907483.pdfIn PDF document text
    • http://artstudiodesign.it/userfiles/files/59418587276.pdfIn PDF document text
    • http://myphamnanyno.com/luutru/files/xexubotepora.pdfIn PDF document text
    • http://movesearchesuk.com/userfiles/file/soropirude.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/rominafabixogej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=codename+redmi+note+8+proPDF 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_off0000dddd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDD 10580 bytes
SHA-256: 8b223d05d0c3762bd4ef0dd6fba92ee5280c12d76c5d8d22e9dea29dcbe6da63
font_01_sfnt_off0000f5fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E0E 18240 bytes
SHA-256: db0ad130ae975c69ac0f02b58318621947f7dc8e8c4e6a80ea4bc40f2b1279cf