Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5b7331b53de9be3…

MALICIOUS

PDF

70.1 KB Created: 2021-07-02 10:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e0f24a838942fd991f010ad37e29668c SHA-1: e5019c8291f75247076e15afe02c716cf0f10073 SHA-256: f5b7331b53de9be38a601a927a6564a681c33f642a2b658fbbd8ca89438fc5f1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or initiating malicious actions. The numerous external URLs, many pointing to compromised CMS uploads or disposable hosting, suggest a link farm designed to redirect users to malicious sites. ClamAV detection and ML classification further support its malicious nature, likely as a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://ketchas.ru/uplcv?utm_term=mean+formula+for+continuous+series
    • http://mdc.ir/ckfinder/userfiles/files/98029653154.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/a9708b85eb0b1b54307ac05749b96936/59440606006.pdf
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/59c0d5a82725e0c044dd73d01ae6b929/dusulopazo.pdf
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/ieg0krauvmds7j8fbm7kdl4tog/midirawirikujoli.pdf
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160afd12a5c89d---7706638338.pdf
    • http://thuexedanang247.com/uploads/image/files/nupil.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4148730b0d---56339636052.pdf
    • https://bleikss.com/userfiles/file/kezanopixebabolotoxezujep.pdf
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4456d2db95---wuxubafibobitubavigil.pdf
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/3830bbef29e875df523d8d58f5032d0a/57445191841.pdf
    • https://angkoronetour.com/userfiles/file/duropomalirinowizix.pdf
    • http://absigorta.come/file/24598029455.pdf
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/ec954596acb57aea573826b50079a2de/lilab.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bd7d7ec753f---zisusu.pdf
    • http://zs-g.jp/app/webroot/js/ckfinder/userfiles/files/76508612613.pdf
    • http://bezagsecurity.cz/userfiles/31775188972.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1371d348b9---26926640061.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/abd63779d92475ec7b08cd5c6998dc27/zimexivipoguwavisor.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/df6800c9106a7a7cb48e6aa20d9305f0/90035834692.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c91cd07dbeb---telibabifimewejumobuf.pdf
    • http://misterholidaysanprisco.it/userfiles/files/barefitomaxibate.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/e7bea7bfb1f3bc775ba0fa7807243b1e/ketewiwinikewuvemifaz.pdf
    • http://hitecds.com/userfiles/file/bopirefizonosir.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088c22b84ebf---66220760636.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c939ff498b7---5202849419.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_off0000b555.bin
2ae01bdaf61f60f0b9edea25be242ce62b133aa1204125f4a98dd4c4688a963a
pdf-font-stream PDF embedded font (sfnt) at offset 0xB555 10592 bytes
font_01_sfnt_off0000cd7c.bin
73fdd86b65eed1d3bff938dd55c178352e8d5b856d5ca4e16254492a7b48a9ca
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7C 14712 bytes
font_02_sfnt_off0000f286.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF286 16792 bytes