Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40892709ced9faa…

MALICIOUS

PDF

88.1 KB Created: 2021-09-02 14:56:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7e662f0c6365f6190f4803a8d3956d61 SHA-1: cfc11f910624c1e9f23317c2cf0798ce52373681 SHA-256: a40892709ced9faa57c0c52d9b27d01fe3d04d0f77d388b9c09b74ad78914cf4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. These links likely serve as a lure to redirect users to malicious or phishing content, consistent with a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://synerhu.ru/uplcv?utm_term=copy+editing+marks+pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16129b0a332a62---64213030266.pdf
    • http://supermarketdv.ru/files/file/48449848080.pdf
    • http://avesta-hmora.boj.se/uploads/userfiles/files/jisade.pdf
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/nogifuxixarodomejimilus.pdf
    • http://svaz-podnikani.cz/files/file/96737470329.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/mepopazatasudezirix.pdf
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/lenigalamigesi.pdf
    • http://sys-svinding.dk/userfiles/file/jafumemovopudutozuwuzorap.pdf
    • http://travelci.ru/ckfinder/userfiles/files/nekozu.pdf
    • http://tnshoppingbag.com/upfiles/file/somenifazalekasil.pdf
    • https://clap-bas.com/userfiles/file/77338443986.pdf
    • https://biogenetixpharma.com/ci/userfiles/files/47489923487.pdf
    • http://ghioroiu.ro/sites/default/files/file/sixisupabowa.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073e07891425---xonijuzojugun.pdf
    • http://slp72.com/clients/7/7b/7b902bee17765b19ebdde6030f24742d/File/66087040057.pdf
    • https://studiorampinelli.com/file/bonitolezizi.pdf
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/4eg90hji3ue9mq5loilun58eun/rejimeki.pdf
    • http://crosswaysrecruitment.com/userfiles/file/marojitozanezabavejuni.pdf
    • https://fainitelecommunication.com/public/editorfiles/file/49575800142.pdf
    • http://newbusan.net/FileData/ckfinder/files/20210724_7955902D1BD10BFA.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d93a84531a8---tobutafagokeke.pdf
    • https://deniz-sogutma.org/img/userfiles/file/91807292749.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/ff46e60b0c5d07d2e9e7cd87596483ac/dajaludok.pdf
    • http://esoftland.com/userfiles/file/34806284061.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609bfa0f7464b---49485867781.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_off0000f032.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF032 16792 bytes
font_01_sfnt_off00010849.bin
dd4ce3b62108e9eed5c8e685d9689cab251ed8e6cb899ad2453d0f639dea99f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10849 11032 bytes
font_02_sfnt_off000121cb.bin
ac5595f4ab00c75627cc436a0961520254455cd66b79456ac34fbe9f1dd622a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x121CB 19156 bytes