Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5af91269b71da40…

MALICIOUS

PDF

70.8 KB Created: 2021-09-20 20:15:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6041160af05a90a666a527af07a06537 SHA-1: 40ce271a3fe0fb77d243bfbeb3f8275269d23b4b SHA-256: a5af91269b71da40a89feca6b0bf3adaf09edd9acf3eff37185cbaee7026e3a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such sites to host or redirect to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://archism.ru/uplcv?utm_term=temple+run+3
    • https://starfoil-mail.nl/uploads/wysiwyg/tifit.pdf
    • http://metisentry.net/ckfinder/userfiles/files/nilajapaxozi.pdf
    • https://coonvalleycc.com/userfiles/file/tetidurowob.pdf
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/22322e1530f8ff0d2314d4895d6a22c7/purigivigutiravobokevo.pdf
    • http://suaups.net/userfiles/file/6886486475.pdf
    • http://beerskiboot.com/img/upload/file/rejofupojonewivi.pdf
    • http://thesecurityguardunion.ca/userfiles/files/vofikonuzawajiri.pdf
    • http://baracenter.be/userfiles/file/rakukajosem.pdf
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/62073091139.pdf
    • http://z-sinpro.com/upload/files/xifojog.pdf
    • http://bangladeshceramicsociety.com/uploads/editor/files/refopevupuvivebokedenow.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f72c680fcb---dololuvake.pdf
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141bd959a23d---98709559483.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/25b3abb5bb806760d57ae606a42c4e05/zasozudofunod.pdf
    • http://ktai.lmg.jp/upload/file/vojoxamuv.pdf
    • http://vln.nl/files/file/soxudiwuwolozixo.pdf
    • http://hotelbasantresidency.com/uploads/tagalegisakebi.pdf
    • https://ta-taiwan.com/app/webroot/userfiles/files/77836191486.pdf
    • https://avistravel.activsport.ro/userfiles/file/61018166156.pdf
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/zudezuzobafawu.pdf
    • https://artlabjo.com/userfiles/file/89577502599.pdf
    • https://verredistri.fr/xmedia/file/bigegovuribabeges.pdf
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/42345587382.pdf
    • https://incense888.com/uploads/files/202109191020491888.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_off0000b7cc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB7CC 16792 bytes
font_01_sfnt_off0000cfe3.bin
ad2d2a7bba7d5a82883940b04e5844b704721472226a9df2e7482c4acdc12b9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE3 10008 bytes
font_02_sfnt_off0000e604.bin
2c52c9a86340b34b6e23cc12dfdfff65c3af6771f6d9229403fc471799d9817a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE604 15684 bytes