Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bf3209c95209d78…

MALICIOUS

PDF

72.5 KB Created: 2021-09-29 14:16:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1c37db739335c8514a3e2fd503d0c999 SHA-1: 99e2062dd3cd67a3e6a9b65bc6130e00acff4084 SHA-256: 4bf3209c95209d78e4a8c82cb02e4952d07d6c8caf462bf0b5d701d58761696c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple compromised websites and disposable hosting, suggesting an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

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://chcial.ru/uplcv?utm_term=news+of+the+world+online+streaming
    • http://genarchi.com/data/temp/file/66687495210.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16147c8ea11aec---46232702936.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161337872ae7fa---nizomezubuxibifuzapesiler.pdf
    • https://gemwares.com/userfiles/file/54837807164.pdf
    • http://asesorgubernamental.com/images/file/labojotomugubeluvot.pdf
    • http://classicalgardenfountains.com/uplds/file/kovesafawepili.pdf
    • http://yonezawanet.jp/units/24250/zcycom/files/16925404918.pdf
    • http://hkacca.com/userfiles/dasat.pdf
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/1370109640.pdf
    • http://holzbau-napetschnig.at/ladikagefofobogugikeduka.pdf
    • https://minervatech.work/js/ckfinder/userfiles/files/6869040073.pdf
    • https://web-idea.ro/app/webroot/files/userfiles/files/xixiruma.pdf
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/qeho176r96qif5oo268im7plc5/80398290883.pdf
    • https://solidpractise.com/files/userfiles/file/jupibaludasito.pdf
    • http://saaretravel.ee/images/file/tojuwodirowes.pdf
    • https://diarch.in/WYSIWYGImage/file/87483033375.pdf
    • http://esangsok.com/upfile/files/rejujufilitoliwaxirudaga.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161496c3887985---25286390052.pdf
    • https://creteservices.com/FCKeditor/userimages/file/87346337731.pdf
    • http://ktai.lmg.jp/upload/file/tareroxiz.pdf
    • http://allnatureint.com/userfiles/file/1501161521.pdf
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/59885306223.pdf
    • https://apc-algercentre.dz/ckfinder/userfiles/files/14211749356.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_off0000b4d6.bin
3f6181a508a0e7b1cd3db1cd89ef499a0e28abc792164e95b1627f9ed34b615b
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D6 17956 bytes
font_01_sfnt_off0000e381.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE381 16792 bytes
font_02_sfnt_off0000fb98.bin
0130af81154502ccb2c49712e3a3fc22336253e2107c672b42c2b4cc2fbc63a0
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB98 10864 bytes