Malicious PDF — malware analysis report

Static analysis result for SHA-256 88645c874a7ac541…

MALICIOUS

PDF

81.8 KB Created: 2021-09-09 07:24:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 04ca6c09cff45a1099a270b4c870a485 SHA-1: 749be17723bb0ff5cc138f5b4270e0bb1f0d3c00 SHA-256: 88645c874a7ac541342931eb226fa6fd08d3a68a3412ac6e7179321fe0217927
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected by ClamAV as a phishing trojan. It contains embedded JavaScript and numerous external links, many pointing to compromised or disposable hosting, suggesting an attempt to redirect users to malicious sites. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/f030d50d978f206923b3ed0ff3816d83/79526683173.pdf In PDF document text
    • https://anitacalderon.com/ckfinder/userfiles/files/zukotavomegadediw.pdfIn PDF document text
    • https://goodline.by/userfiles/file/xogowa.pdfIn PDF document text
    • https://gangnampools.com/contents/files/wilekujaromeje.pdfIn PDF document text
    • http://meetburgerusa.com/uploads/files/80000287000.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/7528084041.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/xegaresemezelij.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/labobi.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/82248714018.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/nevonoseg.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/161392131f20fb---nunefetiduv.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/nisarureni.pdfIn PDF document text
    • http://battlegrouponline.com/app/webroot/js/ckfinder/userfiles/files/29320104669.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///71589445165.pdfIn PDF document text
    • http://jarosi.hu/files/file/zolinomusazumovilotigumot.pdfIn PDF document text
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/29004781237.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/mafis.pdfIn PDF document text
    • http://urbanposthotel.com/admin/ckfinder/userfiles/files/16062107710.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/88817172738.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/93765551862.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613475f50b502---85407406203.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109051903052895.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/16484172563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=screencast+android+to+ps4PDF 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_off0000d6f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F0 19320 bytes
SHA-256: c787a89c6d8a8770ae78f2d1b6ddaf111593c27beed117dbd4ca1ce2d56d83d1
font_01_sfnt_off000108e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E5 10612 bytes
SHA-256: ebfeda61fb6e4fb846e1a8fe50607f74f4fb63b76fadd4170c0cacd62c4a0119
font_02_sfnt_off0001214b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1214B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1