Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3bf651dda495173…

MALICIOUS

PDF

79.9 KB Created: 2021-09-06 19:04:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 82b7c11f1dc664d052f7214d6d42d25c SHA-1: 1792ba3d9b06f63facc44d34e1faa9b17c205628 SHA-256: a3bf651dda495173ee296c2e185553edf37d0dd88b3a26ea16b81f5c9e687981
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of links, many of which point to compromised WordPress upload directories. These links likely serve as a link farm to redirect users to malicious content hosted on other domains. The ML classifier strongly indicates maliciousness, and the presence of numerous external URIs suggests an attempt to lead the user to a secondary malicious resource.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 5

  • 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://crewmak.ru/uplcv?utm_term=non+renewal+of+lease+letter+pdf PDF link annotation
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a379cd0bbda---8219883661.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/e7lustd5bntpt3j27hama81r5g/29196698290.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210726_FE9E1AF7735CEA04.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/49003289431.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/faf95e2e2813ef9148efc7d2a909c5d5/48866161898.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/82732496539.pdfIn PDF document text
    • http://irths.com/upload_files/files/jomowiwupefebumawezibi.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/74825808594.pdfIn PDF document text
    • http://kennycojewelry.com/userfiles/files/202106/1625076153.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160cff26745e25---joletapu.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160aa95c34d1da---mopagutazugesufurefabiw.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/b74cb516505713ec413a7ccee343ae99/92435725905.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/82f7291772e534c9b34f81d0edc65db6/seritulun.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c20978e44df---75365729502.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/pho4japk6p1emsb0e053jk1if0/45699929610.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/81820700914.pdfIn PDF document text
    • http://cinebuzz.be/uploads/userfiles/files/vofofudibu.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/161341b99d24c6---3498947075.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/45325645953.pdfIn PDF document text
    • https://eklyps.net/images/file/12103127667.pdfIn PDF document text
    • https://abeess.com/userfiles/file/nipaxujogakozak.pdfIn PDF document text
    • 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_off0000d5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C5 17088 bytes
SHA-256: accef265e21a956a3f210cae3bd0618b0e7c2a79fe66f5098009367d16a9532b
font_01_sfnt_off000101e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E9 10460 bytes
SHA-256: e58d32c0118da25ccc8d6081d7c66e9e1e57f66c079892b1f0b4a3c31167a381
font_02_sfnt_off000119da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1