Malicious PDF — malware analysis report

Static analysis result for SHA-256 39272447ca12a56c…

MALICIOUS

PDF

90.7 KB Created: 2021-09-17 18:46:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ac803b4a367025a0a8536f2cb5e77bc1 SHA-1: f41a5d308c83890b204611139a39a6f306058ef8 SHA-256: 39272447ca12a56c9d4d3aac6dc674dbb416c835b17357db088f57b0868b2bbd
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to potentially compromised WordPress upload directories and other disposable hosting. These links likely serve as a distribution mechanism for phishing or malware, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://axi-hohenstein.de/userfiles/file/75036799072.pdf In PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328fb3494b0---82097308658.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/7070216679.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ea42ecc48---64581724351.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/63711904635.pdfIn PDF document text
    • http://speckrepeg.by/UserFiles/files/nikirarexurabipekuf.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/cb7r4otv5qp75g2d3jtpvtd5to/61612613151.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/wokipafojo.pdfIn PDF document text
    • http://goldartline.ua/userfiles/file/88108830609.pdfIn PDF document text
    • https://sskundal.com/userfiles/file/foperoti.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/19097475512.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/61757009978.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/geturesebugum.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/lufatawumi.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/pudawiririwivepiwi.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/62548438726.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/ninupilezobasasemekiwo.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/4cef1cfc560a3c3f2721bf8faeeeb44b/nidofuwuwiripolinuraje.pdfIn PDF document text
    • http://bike-aholic.com/UserFiles/file/10444892116.pdfIn PDF document text
    • https://onlinendttraining.com/files/72453381058.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/bovepavagojosax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=coolest+android+launchers+2020PDF link annotation
    • 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_off0000fd68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD68 18236 bytes
SHA-256: d54489a390fb0ae75444eb87c0d394fceb6a062e467c6e20f08f2f682320829f
font_01_sfnt_off00012c46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001445d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1445D 10840 bytes
SHA-256: abbf56bc78ee3e0f4493e659014741e980ecf8390dd4c99ae7a58c42fb511806