Malicious PDF — malware analysis report

Static analysis result for SHA-256 c99e82885d4d07b0…

MALICIOUS

PDF

82.3 KB Created: 2021-09-29 12:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 639ccc0a97f13f5235ae71433ef125d9 SHA-1: a5856ec7b26221b89235b129ccd2e6c121a0352c SHA-256: c99e82885d4d07b058f4dd70c00ecbabd53f38c15470f329cae5fb959d3bcbd5
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external links, many pointing to disposable domains, indicating a link farm designed to obscure malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or download of further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://mpu-beratung-brendle.de/userfiles/file/81341621579.pdf In PDF document text
    • http://yogasol.cz/ckfinder/userfiles/files/2744574962.pdfIn PDF document text
    • https://tumsad.org/img/editor/image/file/51499725531.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/51752196273.pdfIn PDF document text
    • http://greensketch.in/userfiles/file/1805797296.pdfIn PDF document text
    • http://xn--12cmi2byac9cdhd0hra6d7bxkwbgj1gch.com/user_img/files/37487005865.pdfIn PDF document text
    • https://www.ksmt.edu.np/assets/ckfinder/userfiles/files/89031261987.pdfIn PDF document text
    • http://irfanmakina.com/depo/sayfaresim/file/94942114993.pdfIn PDF document text
    • http://isitekmuhendislik.com/userfiles/file/ruxurebusal.pdfIn PDF document text
    • https://angkalaris.com/contents/files/pugadaje.pdfIn PDF document text
    • http://peoplefoster.com/pliki/65310840517.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/3316681176.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/miwaporixenono.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/47966614863.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/gaxibos.pdfIn PDF document text
    • http://fabriquetextil.com/js/new/fckeditor/userfiles/file/nixazogikimewirukebax.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/27621417021.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/nuvowapoxojuwajizij.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/dazetojofebuwowejen.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/xijivomeperubag.pdfIn PDF document text
    • http://langmypham.com/luutru/files/90173391986.pdfIn PDF document text
    • http://zbirozskepodzamci.cz/userfiles/wikajipit.pdfIn PDF document text
    • http://sweepinstyle.com/userfiles/file/73088643633.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ms+excel+2007+apk+download+for+pcPDF 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_off0000d144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD144 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e95b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE95B 10988 bytes
SHA-256: 57736eccfbf63bfa3e8e022a132b0479d95aa8d3c8e6690f546daf0638c8673f
font_02_sfnt_off00010336.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10336 20412 bytes
SHA-256: fe07dc9e13c49038ee472587befd6f7f5a0e2363985f9f7ebd8466a186d571f8