Malicious PDF — malware analysis report

Static analysis result for SHA-256 389c1ed09e20efab…

MALICIOUS

PDF

74.9 KB Created: 2021-10-08 06:56:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: a57198d080c464f02bec83592b720e7f SHA-1: a981dcc9624ecc136ad0822250933b63eafd1f58 SHA-256: 389c1ed09e20efabf461bf4376f6dbedc9c2f67fe827b96592297f3eac1e36af
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs, suggesting it functions as a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a pattern of using disposable hosting for numerous links. While no scripts were explicitly extracted, the PDF structure and heuristics point towards an attack pattern involving redirection to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://pistant.ru/uplcv?utm_term=simple+linear+equations+word+problems PDF link annotation
    • https://cdmsig.com/ckfinder/userfiles/files/73236904575.pdfIn PDF document text
    • http://mxm-hosting.nl/img/editor/file/biwejufideki.pdfIn PDF document text
    • http://csc0532.com/userfiles/file/20211006065756_wg71kg.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/70678165542.pdfIn PDF document text
    • http://lollanaclinic.com/image/upload/File/dejinexeti.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/f519dbe14efae8c340d6ee5fb8306324/40687945855.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/4196035579.pdfIn PDF document text
    • http://dnestrovsk.es-pmr.com/constructor/dnestrovsk/ckfinder/userfiles/files/96184303686.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/xerexiremerepetamosip.pdfIn PDF document text
    • http://smcertificationservices.com/userfiles/files/24079590983.pdfIn PDF document text
    • http://weforyou.it/userfiles/files/musopuwaxego.pdfIn PDF document text
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles/files/38428271115.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16153cab17af7a---pezozuzirowebuvexifa.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/23271678119.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/13497838740.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/96575031147.pdfIn PDF document text
    • https://softnettechno.com/sribati/editor/uploadfiles/41125593357.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/fulanoxiko.pdfIn PDF document text
    • https://molecult.metallo-tests.ch/sites/web/upload/files/sajenokamogilu.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/77498101597.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_off0000bdfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDFD 11100 bytes
SHA-256: e487c394a0d3a92c56a5e436ebb8353dc1088f08ee08fc35125a28568ecb7017
font_01_sfnt_off0000d769.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD769 17984 bytes
SHA-256: ee5e998cab94b19a0d0bb89126aa15588c7e10246bf8cd9cb027c0a9ae0d19f2
font_02_sfnt_off00010634.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10634 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1