Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5a38885498499a9…

MALICIOUS

PDF

76.4 KB Created: 2021-10-07 05:35:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 958687317b3fd3abdcee2c600381b90e SHA-1: da57ace993aaa54ab54b521c2350b77f73c2524d SHA-256: b5a38885498499a96e456c172aa93d9b485a40c9da28c7a97179fb712af347df
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and numerous external URIs, flagged by ML and ClamAV as malicious phishing content. The heuristics indicate the PDF acts as a link farm, directing users to various disposable domains, one of which is explicitly a URL for a second-stage payload. The embedded JavaScript likely facilitates the redirection or further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=how+to+flatten+lower+abs PDF link annotation
    • http://szjwwj.com/userfiles/file///98649715547.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/salugibotejukeretumot.pdfIn PDF document text
    • https://cqhuaan.myhost360.cn/upload/files/09-02-05-49-46-16.pdfIn PDF document text
    • http://jawarakreasi.com/file/93085128184.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/69055273441.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/28037540387.pdfIn PDF document text
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/77009566533.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/binawozuvaj.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210925022718.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/98639295580.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/31580930444.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/95c1f0e205a85683e5b1cb48e517cef0/57125470185.pdfIn PDF document text
    • http://cuacuontoanthang.com/media/file/65922952928.pdfIn PDF document text
    • http://lycee-elm.com/userfiles/file/20960204728.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/74196805545.pdfIn PDF document text
    • http://auto4-spb.ru/public/images/ckfinder/files/85123846785.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/zosuzipikutuvire.pdfIn PDF document text
    • http://londonjip.com/userData/board/file/kazuvojirejukupuk.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/fekevofopowiwan.pdfIn PDF document text
    • http://sincaremedicaltour.com/js/upload/jemabozezubonugise.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/55984059948.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/653165634.pdfIn PDF document text
    • http://golfvillageonline.com/userfiles/file/9694101819.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/vepefexetexunogorigavubax.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133d8d4dadab---7038400513.pdfIn PDF document text
    • 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_off0000c567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC567 18368 bytes
SHA-256: 9a5c9d54232392d89f9704b555eb798f7e630e962ea72541f2c415edcbe66b6c
font_01_sfnt_off0000f4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4EA 10332 bytes
SHA-256: ab0fcebf6f82b692ef467bacaa0592c48eaed6da9bf5e35dc59ea2191786a277
font_02_sfnt_off00010c68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1