Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d18da5175bb7c3…

MALICIOUS

PDF

79.6 KB Created: 2021-09-24 06:08:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 900f62680da2a79141beba23901f51a8 SHA-1: d3a82db6ab57b4d2702679418aa5e61ea39ded61 SHA-256: 31d18da5175bb7c3e036cab8b3bc88f6977f9d4d6d262f2191ac9e138e1feb86
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites or facilitate the download of further malware. The presence of embedded JavaScript points to T1059.007, and the overall nature of the PDF as a malicious attachment aligns with T1566.001.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7278

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://pamukoglu.com/userfiles/file/naxosapusesovafug.pdf In PDF document text
    • https://bselink.com/userfiles/file/4023579352.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/fubilevewilububawowuduz.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/50465744486.pdfIn PDF document text
    • http://pitin-akutsu.com/js/upload/files/74493326537.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/dobenenugebesuvavomujofok.pdfIn PDF document text
    • http://hongdacable.com/d/files/zisumumelonavodi.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/e2pta7fsj6u7f68fjij7dn3824/79889848645.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/13624745672.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/vatonijelowafi.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/saboti.pdfIn PDF document text
    • http://robvancampen.nl/userfiles/file/nereba.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/54816310814.pdfIn PDF document text
    • http://phucuongplus.com/upload/files/pijanelopi.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/galiguv.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/7947273878.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/lorajuwezajorug.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/a2e8a34ee6ba4d2fde25a48d25ca7b98/buzatasegoladiwen.pdfIn PDF document text
    • https://snpwachq.com/files/js/ckfinder/userfiles/files/14428302547.pdfIn PDF document text
    • https://lmbri.com/WYSIWYGImage/file/50494369646.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/4902720124.pdfIn PDF document text
    • http://study4student.com/cache/fck_files/file/gimugowadapujewaperet.pdfIn PDF document text
    • https://jhservice.net/imagenes/galeria/files/jilufe.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/balotavujirafafuzikifat.pdfIn PDF document text
    • http://s-pack.kr/userfiles/file/20210918120939.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=fifa+2021+mod+apk+downloadPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E7 21052 bytes
SHA-256: 8a245119caa4603b60730858510ca79cba5c36f1fdbdb000c952ba1b25604f71