Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f59db6b5b055f0…

MALICIOUS

PDF

88.0 KB Created: 2021-07-17 18:46:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1bbd934e018764bf63ad9dd53fab105 SHA-1: 897ba6f7450e8925467b2fa76ee8c7f980301504 SHA-256: 21f59db6b5b055f0772b6aa8beea89ed5087306862f810f2dce28db3bc705dc5
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to various websites, some of which appear to be compromised CMS uploads. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates the document's intent is to trick users into downloading a password-protected archive, likely to bypass security scanning. The ML classifier and ClamAV detection strongly suggest malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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 http://verduciautodemolizioni.it/userfiles/file/bepewixovapi.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c01d43a75bf---27316975285.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0098766d5b---65650487096.pdf
    • http://hitecds.com/userfiles/file/lokodafuzugaf.pdf
    • http://brainbond.ro/userfiles/file/86223840573.pdf
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/a1400710fca6b29090d6c0436b465b0b/dinujudalobur.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a869685e386---xisamowatemuxetabujeder.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/6dc4179b40aadc476ade19b404e0302f/71983693320.pdf
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3b6ff167e---34007094202.pdf
    • http://guides2alpes.fr/uploads/file/wutunoxizugi.pdf
    • http://se-ty.ru/uploads/userfiles/file/daxowodosebuvegit.pdf
    • http://marcus-1.com/FileData/ckfinder/files/20210716_C51F7025CE9A0CAF.pdf
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/d0b0c99d5d13a7ef6a02ac48ce3aaea7/lukuvevuzixezizev.pdf
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0136b65731---30691676411.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c6eafa194ba---zakif.pdf
    • http://www.ecostroyservis.ru/File/mexaxubafakixubu.pdf
    • http://choinka4x4.org/cms/files/file/giwut.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070ba6640191---bubodufapuwir.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/4b395b4ec6102de27327d7309dff59c7/47596002529.pdf
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021060305022280554.pdf
    • https://jnvhardoi.org/ckfinder/userfiles/files/sanatasimewoziloxixanoji.pdf
    • http://allprintusa.com/admin/images/file/vewuwonakivisij.pdf
    • http://hoanhaochemical.com/uploads/files/xidetezatolavuz.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/52eecb0bf24fdda86963a8a938eede40/buratulofunetatikipi.pdf
    • http://travellightnepal.com/userfiles/file/jitosegopavejibira.pdf
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/47376427502.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+unlock+a+password+protected+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_off0000f14d.bin
7f4f9ceaeea7a2bfd86ef2265bf399fddb402a14371b410f3280cdd91d7ece36
pdf-font-stream PDF embedded font (sfnt) at offset 0xF14D 17328 bytes
font_01_sfnt_off00011f15.bin
3f6ee66f660f7e034aa44c64b4735efbba9b900cf7a5efefe6c74b47c6871ca6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F15 10792 bytes
font_02_sfnt_off0001382f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1382F 16792 bytes