Malicious PDF — malware analysis report

Static analysis result for SHA-256 537c59752e2aab59…

MALICIOUS

PDF

85.0 KB Created: 2021-06-28 03:09:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3dbacc7830d61c1be9d8638e7144e97 SHA-1: a3b1ea77a106175edc23134da9f7562ef1caedd4 SHA-256: 537c59752e2aab5968ccb3357c338f4472ed281bef2cfc375e194f2ebd58bd33
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, many of which are compromised WordPress sites or disposable hosting. The embedded URLs suggest an attempt to lead users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://www.ecvbrass.ch/user/web/file/jutiwadapapemoroxonuta.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16075703f8192b---69915387695.pdf
    • https://iword.de/userfiles/file/92396608467.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be80faedbe9---sukisusokotivazabakisef.pdf
    • http://rockhouseschool.com/rockhouse/uploads/files/60902525024.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae299e89373---xelelapaluradosigeso.pdf
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/c9de7f4e485b41611869b1ad428f0d8c/powukibipemulaponeja.pdf
    • https://loctra.net/userfiles/file/ritujedixipadezizita.pdf
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160786bb840c00---53167644926.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/a2u3gqvse0hi4tvconjmtvo53q/mofej.pdf
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16073e65580e60---punevogadirumelilotezume.pdf
    • https://digireg.pl/upload/64215892284.pdf
    • https://a2designbg.com/userfiles/file/78942275838.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4c65cae010---guzajemebera.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160905a214634c---jemugosivejolilo.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c1ffa50dd---981943689.pdf
    • http://bagiez.com/userfiles/file/1388685152.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/udn0v3p2mmpeo0onje780v1rpt/54630797691.pdf
    • http://files.ibiza-ferien.de/file/75882321048.pdf
    • https://avistravel.ro/userfiles/file/wugurudas.pdf
    • https://daaeportrett.no/upload/file/48670944970.pdf
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ee07299f5e043e1f4d84a80fc5787b29/tutowi.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/afpbvgpp4sf4cq8k6qpp7nduau/tivadavisoxu.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/37e62c56152e85574b4820e4b062ead7/lumezisoguv.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=cholecystitis+supportive+therapy
    • 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_off0000eb25.bin
6867b3db937e7d57f98d718c59d2c91a9942d473cb74b87d5e5b5a389d560b78
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB25 16492 bytes
font_01_sfnt_off00011600.bin
b6f10836d13af27dd14b6caa703cf179da19315a31c5c6a63dfd8a12949105c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11600 10676 bytes
font_02_sfnt_off00012eba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EBA 16792 bytes