Malicious PDF — malware analysis report

Static analysis result for SHA-256 a48bb073a7446b1d…

MALICIOUS

PDF

78.0 KB Created: 2021-09-03 15:52:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: abe0e77ac334d98415478a8e60b5a0a9 SHA-1: c0f6324140dc6b4a427a483976003360e48e0d95 SHA-256: a48bb073a7446b1d6941478d1efdec4c1bdd4da978af58787f58395f3d4b6807
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Static analysis revealed numerous embedded URLs, many pointing to compromised websites or disposable domains, indicating a link farm designed to redirect users to malicious content. The presence of multiple external URI heuristics and link farm indicators further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://ketchas.ru/uplcv?utm_term=stm8+flash+programming+manual+%28pm0051%29 PDF link annotation
    • https://costabravas.com/uploads/localidades/files/jometebabugo.pdfIn PDF document text
    • https://gkscam.com/userfiles/file/82599011649.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/76191955520.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/gotagamo.pdfIn PDF document text
    • http://kaithompson.com/userfiles/file/sunukawopuwuvas.pdfIn PDF document text
    • http://smart-ventures.ch/upload/Editor_Images/files/10054122191.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/a31a4c1cd08ea3757bf2f688ab976fe6/50469650295.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/wuxijesozalusitepofon.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d37ad909de---90624152816.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/e3n42djtkb2dkgfukii7l47d52/57768492604.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/3932c2c7f8667354adb761e4ffcee828/juporepinupirefarubofe.pdfIn PDF document text
    • http://geoplan.su/userfiles/file/47292231153.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/697651fad9ddebaab8679c4283091d9b/kesewanodudebewonasewejef.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/dakuserifonow.pdfIn PDF document text
    • http://ahchala.com/img/file/sojonulu.pdfIn PDF document text
    • http://sns.hu/_user/file/18456886576.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/pakesufijabibubopafixupup.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca7833ceb3---wipipofudabaxukamidetari.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/s7oa1qecmnl4ojmankhj2em6om/73594604109.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/kifuroteful.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/mijofubobopuv.pdfIn PDF document text
    • http://pc75.net/upfiles/file/1621380600.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/durugus.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/4bda52148707b9d9cb847ab0b7b65b36/48320599288.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_off0000cb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4D 11520 bytes
SHA-256: c8fabd1287b9ffe15129709291717271a34cc959d97bd19a3e9de265b7673647
font_01_sfnt_off0000e683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE683 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE95 17032 bytes
SHA-256: a36351c00c15452c3059510f60f162f07143dfefbeaa0c16014b80b2eb18fbb3