Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3c6165c1deca318…

MALICIOUS

PDF

71.6 KB Created: 2021-09-10 07:49:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ae0610f5afa9e721c0837e6b05517726 SHA-1: d2902544203be80c738269b550ff39c86c083771 SHA-256: a3c6165c1deca318e1068654aa29fa42b89ae4e58da171319b8e4806116a0532
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute traffic or host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 https://vieclamday.com/userfiles/file/75655391556.pdf In PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/ledinojuxijowojufatafamin.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161365a0c54ce2---piwobenapanerovikimupa.pdfIn PDF document text
    • https://netlandschool.cl/files/46583633091.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/a1a231ca9bd076763a3a29945bfe8b69/7762366437.pdfIn PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/gekejefolakikebovok.pdfIn PDF document text
    • https://sdudyogtechnologies.in/ckfinder/userfiles/files/ritapu.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/2760850915.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/liwulezafudetire.pdfIn PDF document text
    • http://suaups.net/userfiles/file/vomidagi.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/5749389911.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/vasozixivojawuxulewofuki.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/4320136499.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/1142613604.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/gelugezutidijomidabesav.pdfIn PDF document text
    • http://mrspk.com/ckfinder/userfiles/files/63932023527.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/33358655747.pdfIn PDF document text
    • http://jinistudy.com/_UploadFile/Images/file/29788171477.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16134db5d301f5---tikizevaburotoketilu.pdfIn PDF document text
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/9129098523.pdfIn PDF document text
    • http://elazentrale.de/images/uploaded/file/55204319019.pdfIn PDF document text
    • http://9275522-travel.com/userfiles/file/51881758867.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/72704097356.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/lbrljren9v2ljm6ch5n14gda80/dimazuj.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/15553772173.pdfIn PDF document text
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/53107603866.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=broken+roblox+idPDF 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_off0000b8c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C9 16056 bytes
SHA-256: 83a20b793d763f1f800f69844382f375b82689504eacb74485e7085a3bf8d4d8
font_01_sfnt_off0000e1e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FA 10200 bytes
SHA-256: 9ce34dfa44412a7c0cfafeb103386accc4ca2ad792442e86e24b98728c8a910e