Malicious PDF — malware analysis report

Static analysis result for SHA-256 28635caba0636f25…

MALICIOUS

PDF

83.0 KB Created: 2021-09-22 20:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 149a588897ad076e694c801806b3d228 SHA-1: 92667dfac91554e84ff89e19513a9fda855b6c6a SHA-256: 28635caba0636f25a2fbb48aa8dd203ffdede2b71f8c766e3f743f15563a509b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to various domains, many of which are associated with link farms and compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farm heuristics suggests an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://ketchas.ru/uplcv?utm_term=robinson+crusoe+pdf PDF link annotation
    • http://musiclivemarsala.com/userfiles/files/tibokiresapu.pdfIn PDF document text
    • http://azseal.net/uploads/userfiles/file/26759659710.pdfIn PDF document text
    • http://theprofitnesstrainers.com/userfiles/file/kubawiretewaminofuroli.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/61257191021.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f2aec738c---toripivejojibol.pdfIn PDF document text
    • http://adria-ex.com/images/blog/file/jazexofixadilonaxeb.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/dusajajidujebalezomudi.pdfIn PDF document text
    • http://vkp.ru/upload/global/file/15993254194.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/wugilekeninuwajakolagubet.pdfIn PDF document text
    • https://www.sterlingsez.com/ckfinder/userfiles/files/jetifemapulawok.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/161493999e9a79---32177859218.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/moselaviwirafilixasur.pdfIn PDF document text
    • http://shopabrang.com/images/files/24416871121.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145e9c5460cb---60111507971.pdfIn PDF document text
    • http://telecycling.org/files/file/dotaridugo.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/aca7b873f94ab890a4e7e32027efe779/jurogaf.pdfIn PDF document text
    • https://et-auditing.com/userfiles/files/wanap.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/655049133.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/28376143283.pdfIn PDF document text
    • http://accutindustry.com/Upload/files/20210921050436.pdfIn PDF document text
    • http://talesma.com/E/file/51755047854.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/1632470069.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_off0000df8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8A 17960 bytes
SHA-256: b14258ee9caf2bc86fb155c4bb0cf9ffb11b645e2a734f054549fc6ad7b360ed
font_01_sfnt_off00010e7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E7B 10592 bytes
SHA-256: bceff63f993c997faf617bcbd5b66945948e2f83aeb71f9ea340fb9a0912095c
font_02_sfnt_off0001268e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1268E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1