Malicious PDF — malware analysis report

Static analysis result for SHA-256 372099c1756ea045…

MALICIOUS

PDF

84.5 KB Created: 2021-09-13 07:29:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f2b262aa4933f54d0862f3bd8a2f4bbf SHA-1: 8a835c61d9127beeac31aebd4fd36265bcee6762 SHA-256: 372099c1756ea04579c79225e0ac596913d7c841fe1108eaa973ab1f7c561ffa
156 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on compromised WordPress sites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded URLs point to various PDF files, suggesting a redirection chain to a final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac36c9b670---gizifisa.pdf
    • https://heritran.vn/uploads/news_file/6123719362.pdf
    • http://ski-experience-japan.com/images/blog/file/tozerodozogiseri.pdf
    • https://produktybhp.pl/pliki_user/File/gipepimasuvabijijozelev.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/678179c88e34ef88567510a5eece514e/33476789571.pdf
    • http://confidence-ist.com/ckfinder/userfiles/files/37490330353.pdf
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/73288540600.pdf
    • http://moto-bike.pl/userfiles/file/70330043906.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135fc78d180f---58852334154.pdf
    • http://dancephoto.ru/userfiles/files/diwozorusovemugivewafota.pdf
    • http://ibconsulting.it/userfiles/files/76788241652.pdf
    • https://decoveinvestment.com/userfiles/file/7864738933.pdf
    • http://abacusnancy.com/userfiles/file/buwivimukelusaf.pdf
    • https://tierrettung-in-katalonien.org/ckfinder/userfiles/files/gigojezirozu.pdf
    • http://pvvc.cz/files/81846874383.pdf
    • http://langeline.com/ckeditor/upload/files/zopasepigiwubedugoladese.pdf
    • http://www.thaitofu.com/image/upload/File/kuririmomebatedop.pdf
    • http://prompol.com/media/file/78194895642.pdf
    • http://mg001.cn/upload_fck/file/2021-9-11/20210911043834957886.pdf
    • http://goldstecq.com/userfiles/file/59560951301.pdf
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16137923934cc2---jebotupuwore.pdf
    • https://camelcarpet.org/d/files/75310893792.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=install+ubuntu+dual+boot+without+usb
    • 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_off0000e713.bin
04efb15d46d4c2637007684524f0b4e5ce3f37222bf2db4d93346908da654e76
pdf-font-stream PDF embedded font (sfnt) at offset 0xE713 10388 bytes
font_01_sfnt_off0000fe85.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE85 16792 bytes
font_02_sfnt_off00011697.bin
84135ce8372433dda771652e7e92e506dbe1674b382d259d505bfbeef2e1b1b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11697 17816 bytes