Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac21a87444b10312…

MALICIOUS

PDF

77.5 KB Created: 2021-09-21 15:53:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 175f2d5c5f29952200bed388a3e524cd SHA-1: 54eed9e211d5be065d96d69bc085bad6631e7723 SHA-256: ac21a87444b10312e591994c66ed0a5e57d90a5eb7d9d92ed07775e5954256ef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits vulnerabilities or contains malicious links. The heuristics reveal it functions as a link farm, directing users to multiple compromised or disposable hosting sites, which is a common tactic for phishing or malware distribution. No scripts were extracted, but the PDF structure and URL patterns strongly suggest an attempt to redirect the user to a malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://kruengrangthai.com/files/files/90802918556.pdf In PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e54b2a67f5---6694650449.pdfIn PDF document text
    • https://infosantiere.ro/userfiles/file/4662135345.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/37969626521.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/gunokepupemidozibefoxero.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613889c1198e9---galumizasunizuwaw.pdfIn PDF document text
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210910_7376E12AF6501E59.pdfIn PDF document text
    • https://pcetravel.com/files/file/68108472567.pdfIn PDF document text
    • http://www.fuchingrading.com/upload/file/jemejugetetevivufadudubek.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/38689813108.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3a5e18c3a---xefafi.pdfIn PDF document text
    • http://holidayservicemarsala.it/userfiles/files/waburof.pdfIn PDF document text
    • https://bawauang.com/contents/files/winemoxiridopagim.pdfIn PDF document text
    • https://novitas.ro/files/29876081839.pdfIn PDF document text
    • https://chowdhurytourism.com/ckfinder/userfiles/files/mikuziwadalus.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/xipadufef.pdfIn PDF document text
    • http://spl-designs.com/ckfinder/userfiles/files/sodapowenuzawawegemap.pdfIn PDF document text
    • http://zhongguohuachun.com/d/files/vuborulisegadipu.pdfIn PDF document text
    • https://1tlstar.com/storage/uploads/files/7050882945.pdfIn PDF document text
    • https://marcvandewiele.com/userfiles/file/pamapuxodatofabuvoko.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/89541319745.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/wokixevedoxiterujime.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=fancy+pants+1+unblockedPDF 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_off0000ca5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5B 10792 bytes
SHA-256: 4a146560fd444419425e64931f8c37ad88bcd49c46a52b0738d3ef984428250e
font_01_sfnt_off0000e338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE338 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB4A 17684 bytes
SHA-256: 4689c8398f549bd9c523b2b805676a00b39ed4cf83113980d8fa302451de8ad9