Malicious PDF — malware analysis report

Static analysis result for SHA-256 544aa707d7031fc8…

MALICIOUS

PDF

86.3 KB Created: 2021-09-06 11:54:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e37865a18c166f782c7dd51f636668d8 SHA-1: d121d071d28a3628c677241998aad9dcf360934d SHA-256: 544aa707d7031fc85e9583395789ad59a0dba643a1c9bae00aa6c1bd0d6e8f54
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The ML classifier strongly indicated maliciousness, and multiple heuristics identified the PDF as a link farm hosted on compromised CMS uploads. The document body is heavily obfuscated and appears to be non-readable content, suggesting its primary purpose is to host links rather than convey information. The embedded URLs point to various websites, many of which are likely compromised or disposable, indicating a campaign to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/s9247avqsqtng84uhu81qjqvo1/19544342518.pdf In PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b8cac4ba63d---dexosi.pdfIn PDF document text
    • https://orderpoet.com/ckfinder/userfiles/files/vuferofefubemerekoraxude.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609e606c116a0---43919107526.pdfIn PDF document text
    • http://fanta-life.com/userfiles/file/toxemepomoxeruxepob.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/63684948862.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/zaboxo.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16087ef1f18663---jotakasipikog.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-5-30/20210530222750625252.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/fekasijizubof.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/72467838391.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160869fbfde03d---97035927541.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/3c84cc8d80547d087044a1fb66d65eb3/kaxuleleloxusapodudix.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/75693442685.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c3fdb456492---78376029432.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/17604287491.pdfIn PDF document text
    • http://st-johnson.com/Uploadfiles/files/98223774699.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/9529c4871e1e0276462b98684a0c1430/26395509308.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b564551ccb4---97885373271.pdfIn PDF document text
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/2b94c622942078486528ce85e9545883/41085994190.pdfIn PDF document text
    • http://hennel.hu/sources/elemek/file/lovirenuza.pdfIn PDF document text
    • https://careerroots.net/ckfinder/userfiles/files/bifumesa.pdfIn PDF document text
    • http://resetimpianti.it/reset/public/file/43598558824.pdfIn PDF document text
    • http://mmdplus.com/userfiles/files/20210703_040825.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=animals+names+in+tamil+and+english+with+pictures+pdfPDF 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_off0000e79c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE79C 11116 bytes
SHA-256: d3f2ca3a69afd46a729fa4f9fc06a04ad196debffb63f02a8d9818d2bada5951
font_01_sfnt_off0001012b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1012B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001193d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1193D 18912 bytes
SHA-256: 87eaee215cf8706aae94e76ac4c9215a6bfd084f86cd654dce076c5c512c95c9