Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b774e4ae91674df…

MALICIOUS

PDF

70.2 KB Created: 2021-09-21 11:25:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2edd47231a318a2695499b06756fff39 SHA-1: a5734fbafb3805ee0d40e62c1a589a08bbb07c5d SHA-256: 4b774e4ae91674dff389e58e7a6f722c651e9968d1e3d74d63bdb1657e7e0258
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 http://yuha.be/_files/file/jozuzuwexiwamog.pdf In PDF document text
    • http://houstontca.org/Content/uploads/files/mezizabupag.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161344d184f5b3---27423076866.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/lufonu.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/86da6f50a3a32236079345d30a4a92fd/natekitorolupunoxaliweb.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/nitulajuxebutuwarafo.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa9304e54f---7153133005.pdfIn PDF document text
    • http://www.portaldasfreguesias.com/portugal/vianadocastelo/vianadocastelo/geraz_do_lima_sta_maria/ckeditor/ckfinder/file/62010038434.pdfIn PDF document text
    • http://namngonviet.vn/user-/files/97090675704.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/53857445039.pdfIn PDF document text
    • https://parfumzone.ro/files/file/tusebisosiradafopuzinibar.pdfIn PDF document text
    • http://potlista.com/file/files/rogabezufatukaruru.pdfIn PDF document text
    • http://goldenteriyaki.com/uploads/files/45332927542.pdfIn PDF document text
    • http://icareonline.net.au/ckfinder/icare/files/zewulomesuluwaxibijojefu.pdfIn PDF document text
    • http://ats-dz.com/userfiles/file/18737017581.pdfIn PDF document text
    • https://vos-web.nl/userfiles/file/xuzovewudabijuzital.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce345ae1fb---xujaxefevogifigitipuje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=moon+lovers+season+2+watch+onlinePDF 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_off0000acea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACEA 18352 bytes
SHA-256: 614c07ed84e23b16333db2e9df2a7f327008f0cdd1a6df0f6ab52c98170382c9
font_01_sfnt_off0000db98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 10592 bytes
SHA-256: a33e574c62f0167cd65245bd2735a24d1ddfd776407fee91a93be5494c216c87