Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5a0d44f4d51d1fa…

MALICIOUS

PDF

76.3 KB Created: 2021-09-11 21:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3316b3b824874b39e20bacf5213d083e SHA-1: 864ed143e0129665e6829232decbcfcd869975ee SHA-256: f5a0d44f4d51d1fac662eb1f7eab120f039de48a5bcaf1d62ddefa74a7ff914b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The structure suggests an attempt to obscure the final destination through multiple redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://www.ventisilva.com.br/ckfinder/userfiles/files/5156002429.pdf In PDF document text
    • https://dcoderesearch.com/uploads/61028161164.pdfIn PDF document text
    • http://bjbtrh.com/files/pic/file/73958215260.pdfIn PDF document text
    • http://biomax.shop/filespath/files/20210901055058.pdfIn PDF document text
    • http://samsungdvm.net/upload/ckfinder/files/50061926954.pdfIn PDF document text
    • https://bahamianbrewery.com/ckfinder/userfiles/files/jupoluxojebuto.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/87695150004.pdfIn PDF document text
    • http://infoegrafica.com/userfiles/files/bajufatuxusixewuxifuxekuv.pdfIn PDF document text
    • https://agrando.cz/files/file/zizijozigavud.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/xepuwedasorusuguge.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6dddeced3---14566944223.pdfIn PDF document text
    • http://ohana1bbq.com/uploads/files/nemujodamumur.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/zolepubowobekivabegujutem.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336b8041b9d---51448984748.pdfIn PDF document text
    • http://net-work.cz/data/file/xopadisidakijig.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/82cfd665576c795e7143ee91e6f4af3a/66250630055.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/tofotibofita.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/mugopagexeko.pdfIn PDF document text
    • http://gdwtechnology.com/fckeditor/file/jabamoxumujuruwedel.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/61263891349.pdfIn PDF document text
    • http://indianspringhomes.com/userfiles/files/sisenilesexexuxiwenu.pdfIn PDF document text
    • http://edukoc.net/userData/ebizro_board/file/79018036903.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021091001285673499.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=word+replacement+androidPDF link annotation
    • 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_off0000c596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC596 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDAD 10500 bytes
SHA-256: 6d25e508db93b3f5cb57a21891144b6dae45b213805136d0befc9f176df1e290
font_02_sfnt_off0000f57b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57B 17844 bytes
SHA-256: 40e0f0bf88bb0a3aa397c3dfc01b65d7e30a7f64f817802cdc413bc9d263e766