Malicious PDF — malware analysis report

Static analysis result for SHA-256 c68740fe11d1e487…

MALICIOUS

PDF

71.3 KB Created: 2021-05-28 17:21:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 21b4f3f58ca882e7d6a9c403931e335b SHA-1: cfad6e64a9d22743ca40c0ac32953642906421bf SHA-256: c68740fe11d1e4870cd03cf84daf38c41e8513c39a9659db3bae6e67c54a3474
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to PDF files hosted on link farm services, indicating a potential SEO poisoning or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and extensive link farm are indicative of an attempt to direct users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/123?utm_term=kgf+ringtone++tamil+masstamilan
    • https://sumikoxivabozo.weebly.com/uploads/1/3/3/9/133997645/e826f.pdf
    • https://static.s123-cdn-static.com/uploads/4369494/normal_5ff17ce77ff6a.pdf
    • https://static.s123-cdn-static.com/uploads/4411512/normal_5ffdafea512e7.pdf
    • https://nugukivi.weebly.com/uploads/1/3/4/8/134894856/ac6b67.pdf
    • https://zizizibewanexu.weebly.com/uploads/1/3/0/7/130776642/xuzupagijojo_sibovanijibivu_vaxak.pdf
    • https://static.s123-cdn-static.com/uploads/4382190/normal_5fc7932239848.pdf
    • https://kowedeta.weebly.com/uploads/1/3/0/7/130775164/5bf02.pdf
    • https://static.s123-cdn-static.com/uploads/4404990/normal_5ff4d334c7357.pdf
    • https://cdn-cms.f-static.net/uploads/4401714/normal_604ad90c104fc.pdf
    • https://xowozasa.weebly.com/uploads/1/3/3/9/133999953/xeranuv-vuvuvevi-balokesulabek.pdf
    • https://pasuwuzo.weebly.com/uploads/1/3/1/4/131438486/povizobisewaridoj.pdf
    • https://static.s123-cdn-static.com/uploads/4375885/normal_6007dbd0b0e54.pdf
    • https://cdn-cms.f-static.net/uploads/4497093/normal_6020c1e951598.pdf
    • https://static.s123-cdn-static.com/uploads/4477138/normal_5ff32bccd8c22.pdf
    • https://static.s123-cdn-static.com/uploads/4457296/normal_5fe5843feac11.pdf
    • https://static.s123-cdn-static.com/uploads/4485693/normal_5fc9e8f54912f.pdf
    • https://pikupazu.weebly.com/uploads/1/3/4/5/134577858/tojikemojupalu-lunojel.pdf
    • https://cdn-cms.f-static.net/uploads/4487192/normal_600fe5655863b.pdf
    • https://nofexozodaxo.weebly.com/uploads/1/3/4/5/134522082/fesarixa.pdf
    • https://static.s123-cdn-static.com/uploads/4483873/normal_5ffbaa2f1cb61.pdf
    • https://xunujilitaga.weebly.com/uploads/1/3/5/3/135315779/bejexegaxek.pdf
    • https://melokiziw.weebly.com/uploads/1/3/4/6/134669089/kibagabirefamuwok.pdf
    • https://static.s123-cdn-static.com/uploads/4451208/normal_5ffe128a6d560.pdf
    • https://cdn-cms.f-static.net/uploads/4451753/normal_5fdba12e8fb94.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da64.bin
c99b9e6dfd98efbe4a2a3c1c353cb945ee91e4e2c4b754980f714249cb0338ff
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA64 5056 bytes
font_01_sfnt_off0000eb8d.bin
5608e25a3ad16051df5b8232009243bb523a8b06878c40145c192a7a41d8f4a3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB8D 10616 bytes