Malicious PDF — malware analysis report

Static analysis result for SHA-256 51357e97d5d90ffe…

MALICIOUS

PDF

72.8 KB Created: 2021-09-25 17:20:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1e129fa50b820c59bb366247234bf7c SHA-1: c12af8a882c64060cbdd54c6215c08f80d53ac7a SHA-256: 51357e97d5d90ffe1d0a766f704974e40521d8c8707c85e1e902612ebb754241
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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.
  • 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://inwebjor.ru/uplcv?utm_term=how+to+hide+game+apps+on+android
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/99031658706.pdf
    • https://morganmethod.tuesdaytrader.com/ci/userfiles/files/9019979301.pdf
    • http://stapper.de/sites/default/files/userfilesfile/14945395096.pdf
    • http://dolphinkorea.com/files/files/bipekutaxigutitajovawe.pdf
    • http://yas-center.ru/userfiles/file/12188205151.pdf
    • https://newdesert.pl/userfiles/file/25523134885.pdf
    • http://bonezi.morefriendship.com/upload/files/45938963173.pdf
    • http://ge-mak.com/files/kezinemovutito.pdf
    • https://my-natural-style.net/upload/files/90445672341.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394f01e4486---58607941560.pdf
    • http://studiotecnicomartani.eu/userfiles/files/dowuzabozuborubopixepimid.pdf
    • http://naplesredeals.com/userfiles/files/wixevitulojuselodawemurar.pdf
    • https://wedding-photos.cz/userfiles/file/buwukijijivanonoveku.pdf
    • http://cycling-software.com/files/file/koxeputor.pdf
    • http://dui-antidote.net/images/userfiles/file/32248409394.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/65it9ju6dvarbks75feqkrdl71/99312907766.pdf
    • https://tekmaker.com/upload/files/wokisamitarirubigodamepi.pdf
    • https://efficimm.fr/userfiles/files/21113227428.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e1b5a36cfe---69824140996.pdf
    • http://kliknetezde.cz/admin/obrazky/file/safilat.pdf
    • http://antansconstructions.com/ckfinder/userfiles/files/rewenadedefefumow.pdf
    • http://recepti.plovdivweek.com/js/ckfinder/userfiles/files/zavagadesawoluko.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b92518d417---pileginigelox.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_off0000b508.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB508 16792 bytes
font_01_sfnt_off0000cd1f.bin
73dd993ecc979039bb24ea8e856048b6e027715d125535b0274a3505efcf7dd3
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD1F 10868 bytes
font_02_sfnt_off0000e5d8.bin
5a9475c7fa4a62056cf1648dad94afca5ee205b1214cf079958da61c1910098f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D8 18276 bytes