Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1f3445afa8c41d2…

MALICIOUS

PDF

73.9 KB Created: 2021-04-28 02:35:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 23c56988d75d2db4d69d3be3f0717a56 SHA-1: daa44fc4e0b7ce595136b606de9521956c2ea242 SHA-256: f1f3445afa8c41d2f4820e3aeca4155c39de63e10a87887802376ba1bd4d9d57
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites, likely to host malicious content or further phishing attempts. The document body, though heavily obfuscated, suggests a lure related to factoring polynomials, aiming to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8924

Heuristics 5

  • 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
  • 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://www.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/aecc763da2989e1917d6aa924122cd7d/soxidepomo.pdf In PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/1u54h8lmom4cn4p26v9aj422q2/23895571897.pdfIn PDF document text
    • https://www.haievent.com/wp-content/plugins/super-forms/uploads/php/files/vh208kgmfoqrq8kun8nf1gij4b/lebemidavozivipakivado.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb2969c809---kumujenaworawowuvopadixa.pdfIn PDF document text
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/91ff2a0ce7cfdef398cfa8b1f8994278/77572165201.pdfIn PDF document text
    • https://medprobr.com.br/wp-content/plugins/super-forms/uploads/php/files/960a0de6505efb3fac64e3dcab995b50/22977251517.pdfIn PDF document text
    • https://stegopackaging.com/wp-content/plugins/super-forms/uploads/php/files/d8197ga7a0drt6uek12svjbhv0/80036473882.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/7aaab6fbfb58e971411b4fcd2946f029/telikolifovixumidubino.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608863f5d5b62---muderitudivepudelekapad.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/1b46116af1648228193016ac1b1a34c1/zedejozagosoxof.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/2sqjh5j6hsqcku6evntgk3nup1/zaropalobisozemugunafu.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/ba70e99f1215a742bfa6addb903fddee/xonuwadogasu.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/nevhh2oio0j7c31hkla5be4ap8/xabudafulitofixogowel.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608765d849c10---57053597543.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/805f57de52072e1cbfd37273af85037f/telunasudoxetip.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbbefe8272---29333622666.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=factoring+polynomials+gcf+and+quadratic+expressions+answersPDF link annotation

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010da4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA4 3664 bytes
SHA-256: 7da689fc18874db63b758733cb254571a5da58256e8e4ca6c7511a6eda3dcc35

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