Malicious PDF — malware analysis report

Static analysis result for SHA-256 835658d69cfae13e…

MALICIOUS

PDF

84.8 KB Created: 2021-09-17 15:14:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0898e9a6a046751c20f9bc232a33e338 SHA-1: c542e303fbb93ae24c2eb5e6896d5f4398dc755e SHA-256: 835658d69cfae13e0640b942fdcffdc35c73f36977a547cc7f2e64e8ae755d0d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of an attempt to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://crysiq.ru/uplcv?utm_term=record+sound+from+video+android PDF link annotation
    • http://originalbau.hu/imagesfiles/20168214329.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109010536176139.pdfIn PDF document text
    • https://verredistri.fr/xmedia/file/zugomasixazofuxibagi.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/92270829106.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/68604826803.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161447dea264ef---kagotifan.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/kasipezefib.pdfIn PDF document text
    • http://jinyezi.cn/upload/236659795.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/fvgkll2dju6ns4o3shgmi9vk6c/lelokalujozazibupozolufov.pdfIn PDF document text
    • http://king-tableware.com/uploads/files/202109140531583472.pdfIn PDF document text
    • http://whuntex.info/userfiles/file/nonofuzonefudodurejo.pdfIn PDF document text
    • http://dga.gr/ILC/img/file/32830458502.pdfIn PDF document text
    • https://korankertas.com/contents/files/rapemikokopabibez.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/9162956188.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/191f86fcf2da606f82690d61e4c93180/26955389688.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/bedanowevijafikige.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613df713178ac---mapemebetaw.pdfIn PDF document text
    • http://fpole.ru/sadm_files/86511238572.pdfIn PDF document text
    • https://taichielite.com/louis/taichi/ckfinder/userfiles/files/82866658135.pdfIn PDF document text
    • http://datev.hu/ckfinder/userfiles/files/fuxifuposanuxag.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/radusuwodegakiwekex.pdfIn PDF document text
    • http://missteenqueenuk.com/userfiles/file/fiboxam.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_off0000e67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE91 10704 bytes
SHA-256: 3b4b59e39dac65ebb81bb6e9f5cab0b624146af31ce9ed940732fcc888e0ce47
font_02_sfnt_off00011721.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11721 18164 bytes
SHA-256: 8b878be9c7537111af3b840f745b45245adcb7b60a2767a987a4bd8e212766a1