Malicious PDF — malware analysis report

Static analysis result for SHA-256 623d11530e819445…

MALICIOUS

PDF

81.7 KB Created: 2021-09-12 19:46:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 68c5902d3e659667c4f034fcd01e6c12 SHA-1: b6cc9e8d0b658c0ff718c7e445ecb57c353e6c2a SHA-256: 623d11530e819445dfabf45cfc469377cc2700a8055a7737a835e080e2b127f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crysiq.ru/uplcv?utm_term=handmaids+tale+free+pdf PDF link annotation
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/4ur9hj8fbpqd0h0dl9kjfh5tu8/43004570426.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16130ad5b2691e---95498990922.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/nolakumo.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210911023055.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/falekotovezafotutupono.pdfIn PDF document text
    • http://espicycooking.com/files/file///mowoxosafowita.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-12/20210912202651806774.pdfIn PDF document text
    • http://vectorma.ru/uploads/assets/file/zevuzezew.pdfIn PDF document text
    • https://www.cascatai.com.br/ckfinder/userfiles/files/rusivufosebanoxawegux.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/rajexineboxij.pdfIn PDF document text
    • http://maximaviajes.com/FCKfiles/file/pamisinejitasinuwurila.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/l1sj9ook83haqd856k1ccp813r/mebaxav.pdfIn PDF document text
    • https://webvitamin.vn/app/webroot/uploads/files/23356320545.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec6ff58b39---betopedakuxumedaxafoxi.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/7022669939.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/zudamejepiretuliwof.pdfIn PDF document text
    • https://atrax.hr/files/jupakuvujosikobevazud.pdfIn PDF document text
    • http://xhzhengli.com/upload/51710698414.pdfIn PDF document text
    • http://shamayachts.com/upload/file/92972101132.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/8937081214.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/ribizenu.pdfIn PDF document text
    • http://cissi.it/userfiles/files/9659907875.pdfIn PDF document text
    • http://merrygoldholidays.com/ckfinder/userfiles/files/sutafonibab.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_off0000ddd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDD7 16852 bytes
SHA-256: 8a531e3d1cce50369433b145bcd9da6b112aec7c7d5f1513578ceb5fe607ba29
font_01_sfnt_off00010995.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10995 10528 bytes
SHA-256: c72b9baf9ba54ae3ae4f7d38834d286bd1694bc03ef20981a30695a3773f1022
font_02_sfnt_off00012168.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12168 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1