Malicious PDF — malware analysis report

Static analysis result for SHA-256 09ec48d4cd95bc68…

MALICIOUS

PDF

85.5 KB Created: 2021-07-27 19:03:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 74a553b3835fcfe627c43ff734ed2cc0 SHA-1: 25dd0885003c8ffa3835c83e026493d112deb1cb SHA-256: 09ec48d4cd95bc68752aeb47939237a0666ff261ff6f2fbb9bfe81e107f71cc9
196 Risk Score

Malware Insights

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

The sample is a PDF document that employs a social-engineering lure to trick users into installing a fake browser update or extension. It contains numerous links, many pointing to compromised WordPress upload storage, suggesting a link farm used for distributing malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download and execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160999113d5db3---dupuxifuruvesibeker.pdf
    • https://betalinktech.com/blmedia/file/nalama.pdf
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/lebiritulelezoviwexifat.pdf
    • http://fairway.cc/images/blog//file/47591356881.pdf
    • https://actorconseil.com/files/file/47889661793.pdf
    • http://accronline.com/userfiles/file/soboti.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/ngaqij347nr4ouuramooj1jltf/53607195456.pdf
    • https://noihoithanhtuan.com/media/ftp/file/84540024345.pdf
    • http://kipia-nn.ru/userfiles/file/sekubukajutigewuzozi.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160719ddd65b1c---zegedo.pdf
    • http://jorkurojus.com/userfiles/file/pibosanurosedeked.pdf
    • http://globalroomplus.com/bot/ckfinder/uf/files/38921567247.pdf
    • http://andlupa.com/userfiles/file/bavajovet.pdf
    • http://qunjl.com/userfiles/files/5757913137.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/ugpe8fe1btrikv42rvriia0677/30016062770.pdf
    • http://marinda.ru/pics/images/file/nukeronegibisofumazewasen.pdf
    • http://bigband-ulm.de/userfiles/files/97771498685.pdf
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/b7e560928113b38c441cc3ccd8195a3f/dekogedivijigo.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609f0822a4de3---fefuforogenajavinufam.pdf
    • http://broeinest.org/ckfinder/userfiles/files/11939538655.pdf
    • http://teplospectr.ru/images/files/57390895303.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=adobe+flash+player+update+for+chrome+free+download
    • 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_off0000ea27.bin
6bcfbad3ef288873d6cef4ad4af8fa0c760c56f40f224999aaeba6f871e40947
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA27 16584 bytes
font_01_sfnt_off0001154d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1154D 16792 bytes
font_02_sfnt_off00012d64.bin
6596a823127064d135bff05d77c0d9741a777375d23afa54e77c730aadbff118
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D64 11212 bytes