Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1a3baff12d082f3…

MALICIOUS

PDF

88.6 KB Created: 2021-07-02 11:33:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4dc8f47ad3234e0d5d47f670b8d4622c SHA-1: 29d5f0d825e236990babf6b74059dcf59e36551f SHA-256: c1a3baff12d082f3c61777a0508e69f6d090dd982fbf67c571bc2963b7dc5c44
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple external URLs, some hosted on compromised CMS uploads and disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://sjalikave.hu/pictures/file/53145129469.pdf
    • https://winpoasia.com/ckfinder/userfiles/files/buzuvixer.pdf
    • https://plasy.com/uploads/file/fadigugavunowavo.pdf
    • http://hum-lucknow.org/test/fckeditor/file/39821910806.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee8efe9948---54536518589.pdf
    • http://olgapolyakova.com/files/files/fuxafakasezopisepew.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a3fccb5078e---15495158739.pdf
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/a932e26294aad9ed9857c363fbb5e210/15405007550.pdf
    • http://kelvista.lt/images/files/zuzovubabajamuvomavuzo.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16094c96b2da96---valibiropidonatolutoje.pdf
    • http://jedwines.com/cmsCart//upload/file/59482677734.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16089aa908a77e---zosopukoxilagimelozu.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d8641ceeb1---tobugozasaxowiwefagutikom.pdf
    • http://anoh.net/pds/userfiles/files/zamoponovuxixe.pdf
    • http://hitecds.com/userfiles/file/lanezodabowonizifar.pdf
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/062e8a4d7ffcb810d9711300e46497d5/83660658508.pdf
    • http://debandhelder.nl/ckfinder/userfiles/files/63772106295.pdf
    • http://robalton.es/Albums/images/file///xedigobifazijutiku.pdf
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/d756dc6c60c95adafb7a5de825b34166/tifinepowifijexuzofezi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=eso+how+to+sell+crowns+for+gold
    • 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_off0000f821.bin
62e785bb2b5d827f32ca5c18c5279108605d0df7bf3211056e5f36e85c818efe
pdf-font-stream PDF embedded font (sfnt) at offset 0xF821 17496 bytes
font_01_sfnt_off0001256f.bin
3a8d483e8823d9cea4c1dd5d04469bae567b78291c48f58e270c4da1eaf342a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1256F 10572 bytes
font_02_sfnt_off00013d64.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13D64 16792 bytes