Malicious PDF — malware analysis report

Static analysis result for SHA-256 3538c70588829413…

MALICIOUS

PDF

83.9 KB Created: 2021-09-20 01:54:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 78bff404f2a77ca64520fa72d56be9e6 SHA-1: 11793c143780793da392f1543a7530aa5843d258 SHA-256: 3538c70588829413e3f73fdfd912c336a4fcff97bd54389a955bf1a893ff6cf6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to other PDF files hosted on compromised websites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://wastran.ru/uplcv?utm_term=k+means+and+knn PDF link annotation
    • http://tunecharts.com/userfiles/file/30732726751.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/j15dgj6n1h2ou877v195i0abp1/wunetelumilotelovovefu.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/gomexekesamimop.pdfIn PDF document text
    • http://premiercontractinginc.com/files/file/12755868413.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384b5edc5f9---wexexiwemopegasewijonof.pdfIn PDF document text
    • http://kxxbs.com/uploadfiles/file/a/guvijedu.pdfIn PDF document text
    • https://jagominum.com/contents/files/dotidefufufuvagegoga.pdfIn PDF document text
    • http://tolltisztitas.eu/userfiles/files/gosipenorufimobogak.pdfIn PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/livolibafanaj.pdfIn PDF document text
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/kemobar.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/vasosavanasowu.pdfIn PDF document text
    • http://geose.ru/userfiles/file/76982991916.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16146f12ccac7d---99644649023.pdfIn PDF document text
    • http://e-photosynthesis.org/userfiles/file/binemisexisawujozijapa.pdfIn PDF document text
    • https://gogreenonline.net/userfiles/image/fckeditor/file/66591087144.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/85180426655.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/miwudusopusekasiguke.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/1614562a3eea45---25731893644.pdfIn PDF document text
    • http://ylplj.com/ckfinder/userfiles/files/verutow.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/44625450831.pdfIn PDF document text
    • https://wcfkenzi.com/ckfinder/userfiles/files/26345613953.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/gixokusovunezesunurolapo.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/80180ed9569228b59ef164744ab86b5e/63390404978.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_off0000e1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FB 19040 bytes
SHA-256: 2d2a818a88530485bccd1d455be65a5831b7fe0955ce0d185ea96826c7a20d95
font_01_sfnt_off000113d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012bed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BED 10036 bytes
SHA-256: 7ec799145d0a4f81e77e952c24b48a5552bf0c30666c824efc84f09907d16dc1