Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8eea49cd89918f…

MALICIOUS

PDF

80.4 KB Created: 2021-09-20 00:17:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 981e73154c207891d4b4d202d62d90b4 SHA-1: 44e07a5288429436649483fd3d8be9b4d9fcce5c SHA-256: 5c8eea49cd89918f4fd25af1919a0845e8727280ec8ad33e1690a7a1efb97b49
164 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm with numerous external URLs, many hosted on compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=the+best+step+counter+app+for+android PDF link annotation
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/o63n564ppt5uijeepfvdqgk6v7/pigozirope.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/96834626612.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/89627642077.pdfIn PDF document text
    • https://brukspec.pl/upload/file/84809265464.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/wokixevedoxiterujime.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/36405157139.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/xotajegasawim.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/161467c1f7794a---valomomesutavem.pdfIn PDF document text
    • https://hoanghaie.com/Images_upload/files/saterepejaruzijabejani.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16147a69492dd6---xelasoluxelitefizu.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16147a5fdca815---67622023106.pdfIn PDF document text
    • https://silatur.com/js/ckfinder/userfiles/files/65743646345.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/vtkv8j99r02sf11cd5bgp6vrj1/fiwevulem.pdfIn PDF document text
    • http://joyearland.com/ckfinder/userfiles/files/pexoxevapif.pdfIn PDF document text
    • http://sswjeans.com/files/75510111484.pdfIn PDF document text
    • http://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/mozoresumuwoxaxosi.pdfIn PDF document text
    • http://twtipa.com/upfile/files/2021/09/03/36239392618.pdfIn PDF document text
    • https://anjingliar2.com/contents/files/zunokapuwetuwuz.pdfIn PDF document text
    • http://harrodsrentacar.com/public_html/userfiles/file/27741330387.pdfIn PDF document text
    • http://safiorida.dk/operatori/userfiles/file/76095113122.pdfIn PDF document text
    • http://prosquash.by/data/12425716794.pdfIn PDF document text
    • http://warehousetraining.ie/images/tonesibubusu.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/sadiju.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/6fffe069064ced7f90c9c0e890728fe0/resobuw.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/tapoxadit.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://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_off0000d93f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93F 18008 bytes
SHA-256: 55601edd42bb335d78b425e540585d53c852e61f24d74f50f44684c1b92f8dd7
font_01_sfnt_off00010805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10805 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001201c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1201C 10876 bytes
SHA-256: 383067b297dd218e7e6b55f984fb84a3a9bf58a6a81ce3560d633d46731a363f