Malicious PDF — malware analysis report

Static analysis result for SHA-256 4821f3e4b8713cb5…

MALICIOUS

PDF

89.3 KB Created: 2021-08-21 19:06:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aeb795249a1788e57727d376d66a4e47 SHA-1: e961e2c538cc46e93a273fbfa1d4be931f8159f1 SHA-256: 4821f3e4b8713cb5e2e427fdce96c8ea0ea3c7dc34ce2a1d09c615cc406d0973
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised CMS uploads and disposable hosting. The embedded JavaScript likely serves to facilitate the redirection to these external URLs, which are designed to lure users into downloading further malicious content or engaging in phishing activities. The presence of numerous links on potentially compromised or disposable domains suggests a broad phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://synerhu.ru/uplcv?utm_term=lowrance+elite+ti2+installation+manual
    • http://ktcz.eu/files/files/lalepolinomo.pdf
    • http://apexibd.com/uploads/fck_uploads/file/jevinalabexi.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ede2a52c150---20386367276.pdf
    • https://audreyheselmans.com/_files/file/zavegaruseruwutewikogevu.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160f655ca88c0e---30093173509.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608641cb34b69---romibezemewemarijesu.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1611891d66d1e5---71889434441.pdf
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/27c9757f4788badd054ddb093b85aeca/nozelajuriwigitex.pdf
    • http://ekonopuntos.com/campannas/file/zututu.pdf
    • http://rinsacars.com/files/others/tikilijejabadazajimix.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608321f62f257---21689404206.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16083ddd860d75---55401804073.pdf
    • http://rilta.net/userfiles/files/1442897785.pdf
    • http://albino-pitti.com/pub_img/file/goligilepetiwikero.pdf
    • http://interfacetravels.com/app/webroot/js/ckfinder/userfiles/files/45928319935.pdf
    • http://ourgans.org/userfiles/files/levaro.pdf
    • http://markone-tools.com/upload/files/17592800228.pdf
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/86255257285.pdf
    • https://topclassgardening.nl/images/file/lagejatekozoxifenasikijal.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/e4ck4bc45kvo8pvf7eo6r3dqtr/fezodapukenarusod.pdf
    • http://tele-klass.ru/i/upload/files/nodirijowazezozuzumu.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/cdab9c95b82ca81d192ff62adbe96a6f/vobigoj.pdf
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/ca5fb48df4cc4dd42fb366141a5fdc07/jadub.pdf
    • https://rosettes.it/userfiles/file/83688487865.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765dcdf0650---jixefumatimawugukuzum.pdf
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/6b549df2cb055344ae2e2514e6a636c1/kurawejalanokid.pdf
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/2ed8emqupj8c8fi3264dkuoa9f/ginufowez.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_off0000e5c0.bin
54adeadf1ff24e24d2e330498f9c6c26e89b1196790a411cc398789faec844c8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C0 25416 bytes
font_01_sfnt_off00012670.bin
b43b6baca2d599988e6855344c9347a8667875e722c257977d9ca1aa06cfd0d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x12670 10652 bytes
font_02_sfnt_off00013ef4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EF4 16792 bytes