Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9b35e269890fe11…

MALICIOUS

PDF

82.8 KB Created: 2021-08-16 06:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: af9ed1fef6879e930d7cb0b7abf5d0b2 SHA-1: bb8ba479a11cde5b6c02b6afa7e7dc703d709e20 SHA-256: f9b35e269890fe1164886da7a83542c3ad814e4a835dd94409bc3d76a670c0d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as Pdf.Phishing.Trojan. The PDF contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The primary attack pattern involves luring users through a malicious document, likely via spearphishing, to these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160e626bb4237a---luvalazipibenuwifokewugef.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607800e5ab288---bipunagugusizafolugamepo.pdf
    • http://koryosushi.com/uploads/files/9130950716.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16085600b4d4f5---femevapobizij.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160978c174afe2---88831679809.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b29cf7e6b6---18409016385.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ff0001c883f---raxajovilosanoxamuduzom.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/7h6nl6a2cm0t15m6oldlgvib32/21273494628.pdf
    • http://yetisirkaucuk.com/firma/files/muxez.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad4e3453732---38583316514.pdf
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/45fb792c740b38eec52c9be867a59b24/7906210108.pdf
    • http://montagnobozzone.it/userfiles/files/nifegaxoropirafabefituf.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/fd507f9d83d4500c03a64315a2130915/kexexuvanorosamiwato.pdf
    • http://cerezolorente.com/files/cerezolorente/_repo/file/kapebumabamiwepopof.pdf
    • https://planet-for-events.de/userfiles/file/pedada.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7654cad08---29252422197.pdf
    • http://nature-revive.org/files/file/zagibirelosinokilekase.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/i5mkh95o1vrusr23iks6d79284/86226536822.pdf
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b560813e129---soxujoretuvuvomirovowow.pdf
    • https://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/du6u4o9fu76q2rjh4u8hg6fhmo/4002724578.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d55fc0a1682---87914746229.pdf
    • http://poiskvod.ru/images/file/duzexeromikuta.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609f72503e3ef---18474027480.pdf
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/16075f18f8e5a1---60775867277.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b64e9c6dc4c---tivabiwudoferevezas.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=ejercicios+de+analogias+para+ni%C3%B1os+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_off0000dd2c.bin
8473e716543e4d5ce886cc3e2d5bab1bf1321afb998efd5fded3f78964164798
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2C 17584 bytes
font_01_sfnt_off000109cb.bin
a6c8c61e5b0a4e5321d9a75661c51b88f13d15027e7da2103155fceb48ec921a
pdf-font-stream PDF embedded font (sfnt) at offset 0x109CB 11016 bytes
font_02_sfnt_off000122f7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x122F7 16792 bytes