Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4d66c90cc00b4aa…

MALICIOUS

PDF

79.4 KB Created: 2021-09-13 16:52:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dec926eb15a68a85019aec4a5d659cd3 SHA-1: fd7700276335a14e6fa218f0901194d560398a9f SHA-256: d4d66c90cc00b4aa4d6db3776168b943a2d81fb0a0963c66d4788c2ce134b5d5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external links, many pointing to disposable hosting or compromised CMS uploads. These links likely serve as a link farm to redirect users to malicious sites for phishing or malware delivery. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/uplcv?utm_term=how+to+decrypt+a+sd+card+on+android
    • http://zhongjiukeji.com/upload_fck/file/2021-9-4/20210904193352380320.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab344cf189---91267873185.pdf
    • http://jeansresource.com/js/ckfinder/userfiles/files/46698781871.pdf
    • http://lnshiyue.com/userfiles/file/20210906092903_450039285.pdf
    • http://lednotice.com/userData/board/file/fisujekajibegoxo.pdf
    • http://epoptavky.com/is/images/FCKeditor/File/vitop.pdf
    • http://slovoveri.org/userfiles/71907418770.pdf
    • http://toyotacri.com/userfiles/files/45631074495.pdf
    • http://studiocinti.eu/userfiles/files/guxovuzuxazedefilupo.pdf
    • http://kubkao-kubpla.com/userfiles/files/bijope.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613edc9d59f79---88272848832.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130aee000844---58160847086.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/5917b9d2f56e313fa73aa7a9413ebd15/lilonugumatedobutikapo.pdf
    • https://laatuwhuisweerstralen.nl/upload/file/nejidesolojivikujak.pdf
    • http://aaas.handyfriendship.com/upload/files/15062408306.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613d75ec541a6---97569945574.pdf
    • https://cupanghitam.com/contents/files/64569914154.pdf
    • http://szyuangang.com/UserFiles/file///sivorenewisarexu.pdf
    • http://www.jindatunnel.com/up_files/file/39869702848.pdf
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161308f0398cc5---85029388542.pdf
    • http://gewald.ru/content/Files/62350340680.pdf
    • http://influences-vegetales.eu/assets/Image/files/17907782859.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_off0000d185.bin
89e378a2a5fd8e73bf4ded19d6f40a0bfb1bd9c95aef1473c3ad346d57ea2cdd
pdf-font-stream PDF embedded font (sfnt) at offset 0xD185 17824 bytes
font_01_sfnt_off0000ffc7.bin
3aa7fae3f5ec4555d87de3927ce0538f998fd7df4e1f848ad2ab1aa65f45e5fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC7 10652 bytes
font_02_sfnt_off00011850.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11850 16792 bytes