Malicious PDF — malware analysis report

Static analysis result for SHA-256 818c5e1e11c8e323…

MALICIOUS

PDF

77.7 KB Created: 2021-09-16 00:14:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a2b91af289caea38c0d6fe7f35385afa SHA-1: 790adc888746656e827e3d31d8d56aa70eaf1e64 SHA-256: 818c5e1e11c8e32399830e61a5e25729682cc6c8e927cee0266fd27ae766bd38
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://synerhu.ru/uplcv?utm_term=cringiest+pick+up+lines+ever PDF link annotation
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d158a1a637---29210842744.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/14106796232.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/masupi.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/12951325955.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/48500142117.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/87223786716.pdfIn PDF document text
    • http://k-ookuma.com/js/upload/files/teluzizurifalizepav.pdfIn PDF document text
    • http://shriramashramps.org/userfiles/file/pexaniboxok.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/86cef42456482cbed4152b32adcac39d/62645633838.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/34118448124.pdfIn PDF document text
    • http://wildzipper.com/clients/wildzipper/userfiles/file/59502311129.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/903e06c3f5081ab40e5a30f31c4434a2/12812789588.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/99456618385.pdfIn PDF document text
    • http://kingsfci.com/userfiles/file/96313080653.pdfIn PDF document text
    • https://stayinbranson.com/ckfinder/triplebuserfiles/file/nuzupugupadubefof.pdfIn PDF document text
    • https://lean-ds.com/upload/editor/file/48445903125.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/38180968873.pdfIn PDF document text
    • http://vistobrasil.net/uploads/file/dofejawozofi.pdfIn PDF document text
    • https://ysh.my/userfiles/file/97045626547.pdfIn PDF document text
    • http://stonestudio.pl/files/upload/file/kozimusir.pdfIn PDF document text
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/99091987721.pdfIn PDF document text
    • http://grupophi.es/uploads/files/2501109964.pdfIn PDF document text
    • https://unibel.pl/pliki/upload/file/66880221986.pdfIn PDF document text
    • 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_off0000cb17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB17 17608 bytes
SHA-256: 51444d5a4c9e0b4e811e4ad9e370924e088b60d815248a4949fb376a02ce9539
font_01_sfnt_off0000f885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF885 10556 bytes
SHA-256: ed303efb660508e0f241cc8de4440f336786198fe4167f120ca728fad306f06f
font_02_sfnt_off000110be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1