Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b91a897777be5f…

MALICIOUS

PDF

88.9 KB Created: 2021-09-23 12:43:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e066320ddd1d669a83fe6ab3377ebce8 SHA-1: 9ad7a5d25997dbf3c0ec19c8e48e1c31f0cdf951 SHA-256: f4b91a897777be5f432ab33c9d98f1d60bd21e30168dcad2a06cbc2a70dd3358
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a ML classifier and ClamAV, detecting it as a phishing trojan. Heuristics indicate the document functions as a link farm, with several URLs pointing to compromised CMS upload directories or disposable hosting. This suggests an attempt to lure users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://thaisomboonautopart.com/userfiles/files/balefe.pdf In PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/j3f127l4kvu7hd33e8f9dig0qc/tusepakitekukoza.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/jolojowal.pdfIn PDF document text
    • http://megamento.com/_UploadFile/Images/file/kojedefon.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3f502cf6c---mogojifegizegapirumi.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/85894926501.pdfIn PDF document text
    • http://e-restauracion.com/app/webroot/files/uploads/files/15370160028.pdfIn PDF document text
    • http://aroma-es.red/yamituki-n/uploads/files/zekasutujowidokuz.pdfIn PDF document text
    • http://professionalcatererspaul.pageindia.com/resume/cms_files/files/24135459248.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/69531835131.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/c56888759fb396977c5331fe13d259f6/86306783334.pdfIn PDF document text
    • http://cdio.vn/uploads/userfiles/file/kidub.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/59ab9cfdd8eb829f9242a6a97d52c228/75283178041.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/nevabired.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/2021921172030.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/28485943000.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/taputufizubilaki.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/zubezedugap.pdfIn PDF document text
    • https://cicimanis.com/contents/files/95095083853.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/10867715339.pdfIn PDF document text
    • https://hearing-outlet.com/uploads/files/202109120936534847.pdfIn PDF document text
    • http://cl-metalparts.com/d/files/62298496165.pdfIn PDF document text
    • http://thebodyclubonline.com/userfiles/file/teviguxemobedosawe.pdfIn PDF document text
    • http://jenistudio.com/upload/FCK/file/rapamujoja.pdfIn PDF document text
    • http://ugyvednok.hu/userfiles/file/42379881233.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+change+your+ringtone+to+a+song+androidPDF 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_off0000f224.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF224 10896 bytes
SHA-256: 3434fb8cabbc2246ff6dc72f57ed2a5a1b4b52e95d81a3c819344248ed686fac
font_01_sfnt_off00010b22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B22 19168 bytes
SHA-256: df1fa1a81fefd43d21f6f837188885bbb6113bbf6f1ab4efc56989f8c2f9447a
font_02_sfnt_off00013d5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D5A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1