Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9d5c3dd91eff11f…

MALICIOUS

PDF

83.1 KB Created: 2021-09-20 12:09:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: af09f2401b455e92cf2981085e509978 SHA-1: f83416b988b0fded85bda796827fbf1c07de8dd4 SHA-256: c9d5c3dd91eff11f46539f76738db78adbc524be872595204255bcf1902c80d5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of multiple heuristics related to PDF link farms and external URIs, combined with a 'Download Button' lure, suggests the document is designed to trick users into clicking a link that leads to a malicious download. The numerous embedded URLs, many hosted on compromised or disposable domains, further support this phishing and malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9886

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://huntic.ru/uplcv?utm_term=xender+apk+download+old+version PDF link annotation
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/24205319163.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/jurug.pdfIn PDF document text
    • http://thepnguyentran.com/media/ftp/file/57979214947.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/022f3a378dc70b731aefe1ff8328275e/58594285771.pdfIn PDF document text
    • https://togeltop.net/contents/files/50211159339.pdfIn PDF document text
    • http://gzhangqin.com/uploadfile/files/29067333180.pdfIn PDF document text
    • https://www.koreayokogawa.com/ckfinder/userfiles/files/97929461707.pdfIn PDF document text
    • http://yoron.net/up/files/wafalenixe.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137f39d74d1f---39605502972.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/33704490783.pdfIn PDF document text
    • https://hgb.se/filer/file/gapalibusa.pdfIn PDF document text
    • http://pokewaveanaheim.com/uploads/files/kolapupusafo.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/27190310556.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/ludulisufimijanej.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210919_C9059B10699A155D.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/c59275834184a1670dda80a94fd70ebb/xarumulimu.pdfIn PDF document text
    • http://classtool.info/upload/files/59575571702.pdfIn PDF document text
    • http://rigassprotes.lv/uploadz/file/83717789079.pdfIn PDF document text
    • http://mondoacquapiscine.com/userfiles/files/pomutukifadu.pdfIn PDF document text
    • http://briquettemachinery.com/d/files/67907612525.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/fukulotijam.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/48f6e5fa9717cd1cad1239512a7f88b4/bifikiwodokedufof.pdfIn PDF document text
    • http://www.cavice.fi/tiedostot/files/vikuzixiguxizi.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#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_off0000e341.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE341 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB58 10540 bytes
SHA-256: f9614e74b5db571a2872ec1c78070358d82d5291cd1da8c4be097a152ffc7e4f
font_02_sfnt_off00011378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11378 19348 bytes
SHA-256: 28ca35886f9c26b94ea14e4b656cf6c0b6210e4d0ef893b6b39e78553175cef3