Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2373044dff4ea9f…

MALICIOUS

PDF

69.7 KB Created: 2021-09-27 13:42:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1ad853df7298d5bd1319a3684d661cfc SHA-1: 2964b407fdf360cb4a251e858dd743e135641e4a SHA-256: b2373044dff4ea9f33e3f0ccb43f8c96846fd919cd813a7362acd3288b75af5a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting. These links form a link farm, suggesting the primary purpose is to redirect users to malicious content or downloads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=king+of+fighter+apk+2012 PDF link annotation
    • http://ulrike-mayer.de/userfiles/files/mixuvawezej.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/bcd12bacc2b52c63b256c5e07346a06e/zejoneposukusina.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/boweremojogad.pdfIn PDF document text
    • https://rajakedua.com/contents/files/wutogi.pdfIn PDF document text
    • http://denprokhorov.ru/images/file/92409906536.pdfIn PDF document text
    • http://pelejas.com/IMAGENS/CKFINDER/files/14103871631.pdfIn PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/labigafokegotikup.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac36a6513c---gupoxosagano.pdfIn PDF document text
    • http://rklatex.com/userfiles/file/fodewopuxijuki.pdfIn PDF document text
    • http://afslab.asia/upload/files/menovefabazomikoreges.pdfIn PDF document text
    • http://speed-r.com/js/upload/files/belotukezuji.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/50751481704.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/94344480998.pdfIn PDF document text
    • https://amt-alarmy.pl/userfiles/file/47837282472.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/potif.pdfIn PDF document text
    • http://jeykrishnaclub.com/images/file/86721572765.pdfIn PDF document text
    • https://renetravel.ro/images/files/88298731762.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/2mm5lh59jremvo84hv5e8s7i93/piponaki.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/161411584543e9---xifisupepelinugonadipisij.pdfIn PDF document text
    • http://cserepakciok.hu/xdata/file/kikimetil.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/86886257045.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/kepefabewurawadomotabener.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/42389951103.pdfIn PDF document text
    • https://posetili.ru/userfiles/file/vetez.pdfIn PDF document text
    • http://avision-italia.com/userfiles/files/punipibole.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_off0000b089.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB089 15828 bytes
SHA-256: 82988c4e1e3c306174f3de79f619ac6fc7843cf0bdf9883cd146201a6cbdf0b8
font_01_sfnt_off0000d886.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD886 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f09d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09D 10800 bytes
SHA-256: 60e260a597b97fdc089612649924bbb3f8fc21334282688e8a27b2a5ff956e05