Malicious PDF — malware analysis report

Static analysis result for SHA-256 3690b51079dc2b9e…

MALICIOUS

PDF

86.6 KB Created: 2021-07-06 16:04:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 9bfa28453d45c1bb3d84454db09f22c3 SHA-1: 3a0d221a0590569652d34a4bc958984ef3593581 SHA-256: 3690b51079dc2b9ed424f84169c4d320ca5a8d7e747bc677ba8be332e91aa790
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to other PDF files hosted on various domains, many of which appear to be compromised CMS uploads. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • 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.
  • 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://iberia-ex.com/images/blog//file/toveleburabadit.pdf In PDF document text
    • http://elementsgogreen.com/userfiles/file/94698803940.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/pesuxu.pdfIn PDF document text
    • https://kaimano.it/file/gabosul.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160af5c3eb479d---53883173904.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606c75a714c8b---zisazobu.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160af5dac42a97---xixanokobusekifo.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/jagekewas.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/10863471925.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/45385116115.pdfIn PDF document text
    • http://santeh.md/img/files/gafovilomizov.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/n3ab2o9mes7j44us2cgkvjl1c0/94716952513.pdfIn PDF document text
    • http://mashtalkandil.com/userfiles/file/wazibafuxudijobigolaxas.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8125e6efc---paguberesosukurukerer.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021052510332273499.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/61941547278.pdfIn PDF document text
    • http://xn--aknmedikal-yub.com/uploads/file/kidoxofed.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/2b53a4b516eaa468b0f9e2e2874b060a/60349242561.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606d683080755---39399535251.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/tozawox.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/4c469dca0d698366ba39d732a6a55a05/namovupux.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c60e37f017a---1913731113.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=lesson+plan+on+electricity+for+grade+6PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE77 11032 bytes
SHA-256: 82377b5f4a98d53559f3e0b95c50ff491d9600f9e52c1ee932cc3a2f07d840a5
font_01_sfnt_off00010817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10817 17108 bytes
SHA-256: b10bdf2a4a80f9cedd2bfc65ea7b70edbd0ddca43a6e46cfc86cf4d91cc345f5
font_02_sfnt_off000134ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1