Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff25bddf2886d919…

MALICIOUS

PDF

74.5 KB Created: 2021-09-02 22:46:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c18342f21897ea00d104ccd732a1c664 SHA-1: 47ed1263ddda95b2700a68f8fd3836d8d13b6402 SHA-256: ff25bddf2886d919bfed6025c01fad7d5f6166aec74d2bf8d1f037d3135ff7fd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs pointing to a mix of compromised CMS uploads and disposable hosting. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a link farm strategy, and the ML classifier and ClamAV detection strongly suggest malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, potentially for phishing or further malware delivery.

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://crysiq.ru/uplcv?utm_term=popper+conjectures+and+refutations+pdf PDF link annotation
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xofozodusiv.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/85394926961.pdfIn PDF document text
    • http://vrtaspol.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/38774160698.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f81a4364dc---zubosorunodinezu.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e7c068323---20624194412.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/16083cdb022545---32467533862.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/vijovudezazivudasizaru.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a5c34588afa---saxidufijirapeba.pdfIn PDF document text
    • http://ags-sib.ru/ckfinder/userfiles/files/pamomowavabalovaje.pdfIn PDF document text
    • http://darienhigh70.com/clients/878490/File/ligosulebojabaxes.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/49479240257.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/6463663f61cdb578793cee7e5335b654/31145402846.pdfIn PDF document text
    • https://www.alitec.es/js/ckfinder/userfiles/files/ziselok.pdfIn PDF document text
    • http://abwingscolley.com/uploads/files/wuvudoxuwef.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078ee94a9415---6645931702.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/18230942810.pdfIn PDF document text
    • http://mrspk.com/ckfinder/userfiles/files/17036920369.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160929f30d504f---gekolepudibemunavawanid.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/65544809007.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/wotakibijamodo.pdfIn PDF document text
    • https://an-professional.ru/img/files/file/bilonewenomogenus.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/48pko0qouuklfjpp4dugb9fjq3/24707285564.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/25093031588.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/liwemotopotezidesatovagub.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/muzimesofesot.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_off0000c05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC05C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD873 10796 bytes
SHA-256: 79ce11a51bdf5d28c4f85791d8ca4d90d75cdab1649ee3228533170b5f3ed866
font_02_sfnt_off0000f16c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16C 16612 bytes
SHA-256: c8120ee82836fb4086e9a2d91e28d32ce6643381f8e7d75a166fc0f7e091608d