Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef90d7d3bd6c0559…

MALICIOUS

PDF

89.8 KB Created: 2021-07-16 01:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 21aadb3b09b175d050e869e1ff4c5dad SHA-1: 8ec61b2363b1b5ea4261821c6c8550d8dd7f4cb8 SHA-256: ef90d7d3bd6c055937344c4c24c5c42134410287a39212ad630f1c077fd7b5b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised websites, many of which are hosted on disposable domains or utilize WordPress upload vulnerabilities. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded URLs suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://irlanc.ru/uplcv?utm_term=zip+code+in+united+states
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/mt1tnnu2bluvi2i5glgfel95o1/bobukezakifapemul.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160d659410a9aa---94146353774.pdf
    • https://nikosdimos.gr/userfiles/file/norirapopajeganel.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/suvoto.pdf
    • http://foodchemsino.com/d/files/37883172494.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/fa072db7b2750ef0a330ac550ea1f944/33082797769.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/trabfsm8uaab7uv05sq4m3kg34/34110990947.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/555ea511210d3e2df555cb8f98d3c7f3/negapo.pdf
    • https://sakkestadbil.no/userfiles/file/99551488330.pdf
    • https://www.oapublishinglondon.com/ckfinder/userfiles/files/kezovosapaxazogosomorov.pdf
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/529182c577db3831b76d296736ac4784/35408096784.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/e61a0f09f6af6a952962448ef95ac797/filaxudemixaxuvabokop.pdf
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b26adfe0264---44376946466.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160800bb562f4f---83827858712.pdf
    • http://pogservice.ru/userfiles/file/kezebomizeziza.pdf
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/bc74b481fe6d93393a900fb90691b694/nupidukumejagutovinuvi.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/o8ul97vj2h1bapl3r4s2flj2o1/11457588282.pdf
    • https://amursvoidom.ru/media/files/gudasex.pdf
    • http://jatyn.cn/upfiles/202106/file/1624385480.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c2acbd48cf3---dozigonekami.pdf
    • http://guides2alpes.fr/uploads/file/58618180858.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160caf78e4bd0a---31163544597.pdf
    • http://xn----7sbabjkhbzbqti4a3apfmdd2s4b.xn--p1ai/ckfinder/userfiles/files/25807821599.pdf
    • https://hitpoint.tw/userfiles/file/30642905718.pdf
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/fd9dd4ff95fb00231ae4f168d03134dc/mafidubax.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a3774e42d---munag.pdf
    • https://daaeportrett.no/upload/file/25827620683.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_off0000fe3b.bin
3da0071f6df168e0d59a6a13c1bab80813342abb88eadfa4e29533a578f025a6
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE3B 16872 bytes
font_01_sfnt_off00012a0f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A0F 16792 bytes
font_02_sfnt_off00014226.bin
7437e3cdbad3f2f3b4f0f8f236ad7577f621109d7b1c204af3ef9dc681b0a093
pdf-font-stream PDF embedded font (sfnt) at offset 0x14226 10424 bytes