Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca5a25b1de8682c7…

MALICIOUS

PDF

84.0 KB Created: 2021-08-21 09:11:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3ba41616385411e9b605add064accb28 SHA-1: 0d84bd2c2cae7b6e0589ae3e3274d9229eb897b3 SHA-256: ca5a25b1de8682c7db702d2a2178122b458152f95d3e7be079c5121ecafe8529
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised WordPress sites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious content or phishing pages. No scripts were extracted, but the link farm structure is a common tactic for distributing malware or conducting phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3b335f047---tudowuniwezivubibidaz.pdf
    • http://jun-travel.com/userfiles/file/xelemozezo.pdf
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608300f0e36e1---97652959681.pdf
    • https://aparcaderoshaddaichile.cl/uploads/images/files/serepenusegevu.pdf
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/435683fa8d2a1a02f18bcab928677a2b/34027864014.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b29b0b18ac---nasibap.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108c94e60614---38563428657.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc7f9737ac5---sogozedefokudeme.pdf
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/2eb15331b5fd0dfb8c43b4c3069fc2a0/4415393125.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/92bd0a5b4068b33eae29b6d4df775045/55638178031.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16085799da3473---zowijigibix.pdf
    • https://istihdamhaberleri.com/upload/ckfinder/files/10631478364.pdf
    • http://unipsyclinic.com/userfiles/file/20210605022547.pdf
    • http://bukhatirhomes.com/userfiles/file/memigenesidagiseviv.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1608fdd096d5f9---lekedivazujovate.pdf
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/16083a33c7a486---bezemegomire.pdf
    • http://www.reenactmentmarket.eu/images/wyswig_images/file/70901684066.pdf
    • https://www.hemoroidklinigi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a7dd03f86---17645062672.pdf
    • http://seoulsquare.com/userfiles/file/gabiledosutolasuvovi.pdf
    • http://buddhavehicle.com/userfiles/file/mutaxazuvisatenijofozake.pdf
    • http://gayaarchi.com/userfiles/file/20210619021352.pdf
    • https://abugfreemind.com/userfiles/file/kixetane.pdf
    • http://whkmradio.com/userfiles/file/49483086853.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/5fafb6445eb21a279fb594f514cd88de/93157780966.pdf
    • https://zagorjeadventureteam.hr/files/48858367919.pdf
    • https://helicopterleasingservices.com/userfiles/files/4713184911.pdf
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5655f9f477---49325446396.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=survivor+season+39+cast+left
    • 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_off0000e444.bin
d3826e4a860c338188fd724992bab2a7543d77d78964540ff56c7d001e7c7884
pdf-font-stream PDF embedded font (sfnt) at offset 0xE444 10912 bytes
font_01_sfnt_off0000fdb1.bin
b255c498990d940647466959e509b07f221302390a2b25c0de0f368469c88904
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB1 17068 bytes
font_02_sfnt_off000129ed.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x129ED 16792 bytes