Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d07b79dbf3194f7…

MALICIOUS

PDF

70.9 KB Created: 2021-04-02 10:59:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 151b30cdc1fba1b2e8483184e6ad1d06 SHA-1: f4d97bebe51a3404cf64737b1fa3b73f5f8b21a5 SHA-256: 3d07b79dbf3194f701b6cf32818a9528a377e083471f6a22ff684661cf5623f8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged as malicious by a ClamAV signature and an ML classifier, indicating a high likelihood of malicious intent. It contains an embedded URI pointing to 'https://pelibifir.ru/award?keyword=juxtaglomerular+apparatus+pdf', which is likely part of a phishing or malware distribution scheme. Additionally, a heuristic detected a link farm with numerous external PDF links, including 'http://jadogog.epizy.com/98371394202.pdf', suggesting an attempt to manipulate search engine results or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9679

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://pelibifir.ru/award?keyword=juxtaglomerular+apparatus+pdf
    • https://cdn-cms.f-static.net/uploads/4386094/normal_6062914b01759.pdf
    • https://cdn-cms.f-static.net/uploads/4450898/normal_6022ce222e496.pdf
    • https://static.s123-cdn-static.com/uploads/4498404/normal_5ffb039dcd800.pdf
    • https://cdn-cms.f-static.net/uploads/4382003/normal_5fdc05f40960a.pdf
    • https://static.s123-cdn-static.com/uploads/4503524/normal_60008a199e0f3.pdf
    • https://cdn-cms.f-static.net/uploads/4452612/normal_606481e87bdf1.pdf
    • https://static.s123-cdn-static.com/uploads/4458849/normal_6003d7b9b87f2.pdf
    • https://static.s123-cdn-static.com/uploads/4498645/normal_5ff007884fc4d.pdf
    • http://niludop.22web.org/darozumizu.pdf
    • https://cdn-cms.f-static.net/uploads/4365567/normal_603a6bb84d688.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://jadogog.epizy.com/98371394202.pdf
    • https://73099f28-10d5-4558-98a1-2f8dc61f1a2f.filesusr.com/ugd/f62eaa_6912c534586b46318fa9d704b61c1b7e.pdf?index=true
    • http://gitogopafo.epizy.com/newapexinamedebeve.pdf
    • https://76bf09fe-c378-4d6f-baa9-beaf48595a8b.filesusr.com/ugd/61567a_9efcd9a967244efba4443189586863ad.pdf?index=true
    • https://933afb0c-60ca-4ff4-ba38-e7c804ca925d.filesusr.com/ugd/941881_53d69d22da9444d0a5fc50a8e45a47c4.pdf?index=true
    • http://zoladev.epizy.com/7866479215.pdf
    • https://9cf93ecd-64ee-4ad6-afcc-f350577a7522.filesusr.com/ugd/c4dbd3_a1c6a8c62148433daa26e6ecc8e0d117.pdf?index=true
    • https://09972071-4174-499b-90b1-de3619f59f53.filesusr.com/ugd/d1c05f_b3eb401a29ec4d789bbb23dd29ba6636.pdf?index=true
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1e7.bin
6ec0c0a1f1f9eee6124f0186c581020b1865b725dbe3e4a72f70a5d7a69a63e8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E7 5420 bytes
font_01_sfnt_off0000f445.bin
f77b60538ab3bca52531f271ccc14265ff8061851adc2c0923dfb558b749dfef
pdf-font-stream PDF embedded font (sfnt) at offset 0xF445 10820 bytes