Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8aa83508b617321…

MALICIOUS

PDF

79.8 KB Created: 2021-09-05 16:19:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a6adbbc84bba9247703bbb41d20b5b96 SHA-1: a493703d87f19bd98024a0c9875e4b17e3fceb60 SHA-256: f8aa83508b61732199fe773ef39af73d90ae65d3f4518dd19842281d2794a9ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://inwebjor.ru/uplcv?utm_term=apa+style+quick+guide+pdf PDF link annotation
    • https://www.passion-rnd.com/upfile/files/2021/08/30/47415944761.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/3355b46bfdfb595e86ab32fc5028d935/33614488068.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/86877061356.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/31932540453.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610ede53bc4c5---85458732798.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/20512922755.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/lesabebij.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/nunow.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610ecfa3aea07---loridosevex.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/jotupodet.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b6db97d8b---6771737925.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/gubevideg.pdfIn PDF document text
    • http://modern-pro.ru/files/file/sikozedawubawezuwajaxeni.pdfIn PDF document text
    • http://schokobrunnen.com/idata/fapavoguponumikujadegu.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160782c79eba37---wofibusij.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/f65a9664d66c718f15adf75dc5899fd5/jiniwutafazunobadujaj.pdfIn PDF document text
    • https://circolodelpistone.ch/userfiles/file/kesuxobuwazilisukirojewa.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/91095064607.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/tosanekotunigumipere.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1610cf742c99fc---nomirupa.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/jubakebugitotij.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/njt8lofos46vrsi5k4iahujk33/62196008509.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_off0000d270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD270 17920 bytes
SHA-256: 23ac3279bc53c96cf4eeb9d9cad6626bec6292a0d463409424a295b7d6170b1f
font_01_sfnt_off00010120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10120 10904 bytes
SHA-256: 4084118b0afe18425a902bfbcd7aba9fc0785addddab9737923493cf94b9a8d2
font_02_sfnt_off00011a18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1