Malicious PDF — malware analysis report

Static analysis result for SHA-256 a88f90b62569a9c2…

MALICIOUS

PDF

68.6 KB Created: 2021-10-02 22:58:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 44b94fd4ada122b8ec360617da58b4c8 SHA-1: 62258d8ab871ef8a40bef65daa2fc6c000cb3873 SHA-256: a88f90b62569a9c2518cb1881e0a4ac8b8448695a448a3abc3237c00440ea4a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of embedded URLs and link farms, such as the one pointing to 'coretry.ru', reinforces the conclusion that this document is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • 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://coretry.ru/uplcv?utm_term=snipping+tool+win+10
    • http://rimini-portal.de/bilderarchiv/file/35236515021.pdf
    • https://mycultureis.com/FileData/ckfinder/files/20210927_3A802A3ED7F82312.pdf
    • http://membranekeyboard.pl/_data/file/24532425016.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef3a2c506e---jexexifesedagif.pdf
    • https://pristineleather.com/userfiles/file/dezisemuvitebipamovud.pdf
    • http://aadcnfgl.netsociality.com/upload/files/55365518307.pdf
    • http://studiolegalezullo.eu/userfiles/files/ramuvufenakituper.pdf
    • http://5lovestartw.com/CKEdit/upload/files/wefadonavimibo.pdf
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zijumirujivod.pdf
    • http://anduong-nhatthanh.com/uploads/news_file/64244701061.pdf
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161438021a1023---sejalepoxikuteluviba.pdf
    • http://zbirozskepodzamci.cz/userfiles/75337536379.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa054767b7---mekoxonozakavuvadi.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/8df55eeb3681b3b839654872044297cc/12364323187.pdf
    • https://hiroyoung.com/data/files/gorogapenikuvunajalol.pdf
    • http://iproperty.ae/userfiles/file/megudibixerumisuxe.pdf
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ef88e94cc3---kigugujetubujenonop.pdf
    • https://soi.icami.mx/ckfinder/userfiles/files/32727661852.pdf
    • http://studiocinti.eu/userfiles/files/73128479162.pdf
    • https://oncallanatomist.com/ckfinder/userfiles/files/50264886918.pdf
    • https://anandalaya.in/resources/file/rusupugevazodajoxe.pdf
    • https://bcbc3399.com/upload/files/25191010277.pdf
    • http://madinagirls.com/easydo%20v2.00/files/uploads/60980996181.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000aefc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAEFC 16792 bytes
font_01_sfnt_off0000c713.bin
c43ca1fff08cedfb1bac02cd5edf1a0d2550af5cbaae7d1766979009ada242df
pdf-font-stream PDF embedded font (sfnt) at offset 0xC713 10200 bytes
font_02_sfnt_off0000de1b.bin
6c3f1cf2c3598a99d876e5466aaebbb8c0569e4b0f50a5c9ccf3e3b525724a71
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1B 15652 bytes