Malicious PDF — malware analysis report

Static analysis result for SHA-256 550eac11fe368be9…

MALICIOUS

PDF

83.7 KB Created: 2021-09-11 02:26:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d0642e99e059456d6a82651732d98c6 SHA-1: fa6ed0bc6e45c5e66b1f51f12022d2024b47af02 SHA-256: 550eac11fe368be91ac90eb02aebcb1d286663edf3770279dbb4c61270146b5d
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to various domains, including those associated with compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://archism.ru/uplcv?utm_term=putlocker+in+time
    • http://global-leasing-management.com/uf/file/24202532529.pdf
    • http://ideviceplus.be/app/webroot/files/userfiles/files/67461488551.pdf
    • https://rolcsi-bau.hu/userfiles/files/mujup.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16137e83ecbdb8---puriguruludakaronaxijonox.pdf
    • http://boras-sjuharad.boj.se/uploads/userfiles/files/68548996818.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/7122e357fe61c1e580ec6b455fb39967/lojuno.pdf
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0b5f462e8---jadegi.pdf
    • http://webinaris.biz/ckfinder/userfiles/publics/files/xizomok.pdf
    • https://agrando.cz/files/file/zizijozigavud.pdf
    • http://bdsps.org/slbdavbatala/userfiles/file/8822271526.pdf
    • http://abwcrainhwy.com/uploads/files/95557729029.pdf
    • http://alnadaoil.com/userfiles/file/robosur.pdf
    • http://sola-brothers.com/userfiles/file/pazas.pdf
    • https://cian.hr/userfiles/file/mipuga.pdf
    • https://areicon.com/images/file/8695853112.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393947d0414---kaluxokirakupupirarur.pdf
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161332cd4ad23d---79287087556.pdf
    • http://piotrkowska77.pl/zdjeciafile/88679114240.pdf
    • https://tidaksusah.com/contents/files/81421340787.pdf
    • http://jilienjrubin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/naderatidezeba.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16139931a678ea---xewuzidibatige.pdf
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89394966494.pdf
    • https://habibitours.net/ckfinder/userfiles/files/vulafotadepifir.pdf
    • 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_off0000dff2.bin
3cf3897c28ec29d65e187dd4999ef51e1566c80f90f70bcbd484e9bf99565d80
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF2 10256 bytes
font_01_sfnt_off0000f6fa.bin
cb75c6db33ea4b62c167f4702afe9fdf7f589ba7a3e6e853d0986a13383c767c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6FA 19348 bytes
font_02_sfnt_off000129d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x129D7 16792 bytes