Malicious PDF — malware analysis report

Static analysis result for SHA-256 5486a8c9b071b79c…

MALICIOUS

PDF

71.2 KB Created: 2021-09-05 23:03:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9218f59007b11a078aeeb4ee7a6bcd8e SHA-1: 9ad96f245a4d4b70c333772310ee0cf11bed9150 SHA-256: 5486a8c9b071b79c727155858599dabc50ca1864ce8da679dfa8a7f359e8a629
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several heuristics indicating it functions as a link farm. Some of these links point to compromised WordPress upload storage, suggesting an attempt to host malicious content or redirect users to phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://intrigantka.ru/images/userfiles/file/87473123909.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4fdda0507---40861262969.pdf
    • http://chpcentre.com/files/file/96557672564.pdf
    • http://unibeauty.com.br/ckfinder/userfiles/files/51370174650.pdf
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2d818eda2e---65299743726.pdf
    • http://www.pics4us.de/userfiles/file/xesiteluvexu.pdf
    • https://jajugroup.com/ckfinder/userfiles/files/33482227658.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/4b78f135fe94ae03b7ff3c1c38a5e63c/bogosomix.pdf
    • https://gachbinhduong.com/upload/file/punekanurafilivubuwur.pdf
    • http://www.vegagastro.pl/upload/file/53779751470.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee31b3e916---71740625045.pdf
    • http://deauville.ru/files/file/ridagedifewafuxomivir.pdf
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/tm4823monp38l6bt5t85c1sdeo/vasifajigowiwakikasi.pdf
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/6gc1ve6cnqnqpbhrm8ebldl9vg/kozerelutifigojuposo.pdf
    • http://artside.org/data/temp/file/86616715265.pdf
    • http://mxm-hosting.nl/img/editor/file/lijawarozizetanixobixe.pdf
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/ko35iefpapgvqugr18b3m9fv67/vafer.pdf
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/2683a16dcbdf25b71b0b2f5363d56d74/bababonapalivuvad.pdf
    • http://barudan.hk/UploadFile/file/20210601153555988.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=letter+sounds+kindergarten+worksheets
    • 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_off0000b4dc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4DC 16792 bytes
font_01_sfnt_off0000ccf3.bin
ce64015c3633348cc3e192b1802fd13f4a5b275ee9b78638570129bd0a099f31
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF3 10716 bytes
font_02_sfnt_off0000e559.bin
6c0097787556fef7573f85d53a324b014c1bad6433e079e21e2ff0a49eb123e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE559 16324 bytes