Malicious PDF — malware analysis report

Static analysis result for SHA-256 893823a45319e4fb…

MALICIOUS

PDF

73.4 KB Created: 2021-09-02 01:09:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: df4c3da5dd1c8fe598a3a77a87301bd3 SHA-1: ebc8add987c995f36fa7e1519b489e4998ddfdac SHA-256: 893823a45319e4fbcbfad13f80119a2c27d95be3edbe1db0f455c78caa102ebd
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a link farm designed to lure users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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=twin+motorcycle+engine+car
    • http://xaydunglenguyen.vn/upload/files/1b1179.pdf
    • http://castudio.eu/userfiles/files/mowupogetamexizob.pdf
    • https://asiastudy.in/ckfinder/userfiles/files/tameziji.pdf
    • http://www.chubsorn.com/file/files/dufifevudipetojaf.pdf
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4637bacace---52211683333.pdf
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/60063466382.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/fa943fd10c5ee2d51a30fc71ef25a8b9/98328229494.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085536127cc0---miroxikerumifozugu.pdf
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160783b44617ea---2625426609.pdf
    • http://fuga-hotel.com/CKEdit/upload/files/76302429274.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/69d6c1f128be4ff59e89eb2212f1defc/bevakixusadiguwonun.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/1a916a756910cc35e16e41b7555dcdb5/88872775707.pdf
    • https://golf-tout-terrain.com/publish/page/file/30221204214.pdf
    • https://dichvuhappyhouse.com/upload/files/73066365359.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b10365a090a---40209598132.pdf
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/bvqt0vjef7g1tef0c1vidmfda6/sutajomu.pdf
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160812fdc21a66---49461578841.pdf
    • https://iaetindia.com/ckfinder/userfiles/files/vibumemim.pdf
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/b315d955f6642925461f8d4f6aec5966/31605422139.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160e0a35a641e0---dulologagisuwetulunapifi.pdf
    • http://tasteofruraleurope.eu/upload/File/sipatedavamag.pdf
    • https://migger.dk/userimages/file/16002471248.pdf
    • https://aldurra.ly/images-editeur/img/file/tatovotizojogezikobopa.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16099a3c308e02---bedutuwevubiru.pdf
    • http://arch-teh.com/pic/userfile/66982973329.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_off0000bfe0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFE0 16792 bytes
font_01_sfnt_off0000d7f7.bin
ad908e00eb7b6fc03be85cf407b7d3658fa1bb753bbaeb39a97df1a4af6814c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F7 10568 bytes
font_02_sfnt_off0000f021.bin
a74fe4430ee22b7f0c363b1f35d2c11c36f4f52ca39e250eed4f4be2ff6e2f5d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF021 15800 bytes