Malicious PDF — malware analysis report

Static analysis result for SHA-256 38e87cf5c84124d4…

MALICIOUS

PDF

70.4 KB Created: 2021-09-01 10:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e940bad57b9d4b879cec31679e9a8c46 SHA-1: eb9d65f0509e30248fbe9e145a24b31f6aabdd14 SHA-256: 38e87cf5c84124d4065a54bf680206bfcc476f1ed512ec336ce49278a03f2960
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The ML classifier strongly indicated maliciousness, and the presence of external URI heuristics further supports this. No scripts were extracted, but the overall structure and URL destinations are indicative of a malicious distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://coretry.ru/uplcv?utm_term=fishing+tackle+shop+near+me+now PDF link annotation
    • https://etonbio.com/newsLetters/images/file/suzipa.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/34cd82ce8ce222bf20ec5357cea9f4e8/pugepigodo.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606dc18cbd616---66066203981.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/pereloxifekelasizufenamod.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/f6fa14e4c71584349187f7e7b772b454/dirasilafif.pdfIn PDF document text
    • https://watosaphotography.com/app/webroot/userfiles/files/20210818_041550.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/sebokegogetipa.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607d84ef2b66a---8054704838.pdfIn PDF document text
    • http://nenorm.com/files/files/73527919582.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e2ae39edf---22953474771.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5545326c0---93275548856.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7503ac13ce---97660998870.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609841d37d38f---rulunebovezan.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/a0326ef8d15455ea9258e9b159185ba6/50188233290.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adb7e84291c---77918978362.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/fodof.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ff0fa81d1---42890611783.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_off0000b326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB326 15572 bytes
SHA-256: 608f17de27d69fabbfb293465b0e5edfae707f763b139db760ee23d25aaf9d71
font_01_sfnt_off0000dadd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADD 10976 bytes
SHA-256: 76c35818564ae78575e84a4008ceb9d60f3fe2d1c785d4fa8d79192de93bdd50
font_02_sfnt_off0000f43b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1