Malicious PDF — malware analysis report

Static analysis result for SHA-256 959977b39a4736bd…

MALICIOUS

PDF

68.4 KB Created: 2021-01-21 07:42:38 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 64698ad8a0ce7a3d6b600bf68d4a8a6e SHA-1: 7254b16e57bcaa934cb8c55e80c17a83d48323d9 SHA-256: 959977b39a4736bd30a3f45d0ec587796203335d13e44578c7ce7069183c9173
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body, though partially corrupted, suggests a lure related to an 'answer key', likely to entice clicks on the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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 https://leonvi.ru/123?utm_term=holt+elements+of+language+first+course+answer+key PDF link annotation
    • https://wetolobumusu.weebly.com/uploads/1/3/4/5/134579125/subovafase.pdfIn PDF document text
    • https://cdn.sqhk.co/goberirud/idBjj9u/techcrunch_news_site.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381964/normal_5fe1b23add3c9.pdfIn PDF document text
    • https://rojogude.weebly.com/uploads/1/3/4/3/134396813/jopuniwufo.pdfIn PDF document text
    • https://danifiwap.weebly.com/uploads/1/3/4/5/134585556/naxofiwa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369932/normal_5f891dfcbf000.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367951/normal_5fc1af4749ac1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392656/normal_5fe09aba4d05e.pdfIn PDF document text
    • https://vexefanakaxaki.weebly.com/uploads/1/3/4/8/134871487/jadofavuvaxa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460045/normal_5fac313c45888.pdfIn PDF document text
    • https://cdn.sqhk.co/xubulozirod/njdyhdL/tamopirutidemugepadulep.pdfIn PDF document text
    • https://cdn.sqhk.co/rogokivika/Nghji1a/63119522216.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4389797/normal_5ff135e5198bf.pdfIn PDF document text
    • https://cdn.sqhk.co/xumirikebixo/aiHjjeh/card_scanner_software_for_windows_10_canon.pdfIn PDF document text
    • https://cdn.sqhk.co/gukokefa/gPzJjaP/badejetenotagen.pdfIn PDF document text
    • https://cdn.sqhk.co/koxopumo/YhcGVhf/teaching_strategies_gold_app_for_parents.pdfIn PDF document text
    • https://cdn.sqhk.co/muzorefu/hejgig1/here_you_go_meaning_in_email.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376598/normal_5f8a60ac097c4.pdfIn PDF document text
    • https://janaravepok.weebly.com/uploads/1/3/4/8/134886337/kofetadanele.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489402/normal_5fdf2a1a93701.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444622/normal_5fa1129f88fc4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/devuxuzejozam/counter_strike_go_mobile_apk.pdfIn PDF document text
    • https://s3.amazonaws.com/dalava/6618975628.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c05d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC05D 5304 bytes
SHA-256: 9423c64bba7a53371d4b94c6710252584aacf476804ca14be27268f26fdf096f
font_01_sfnt_off0000d268.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD268 10148 bytes
SHA-256: 1e914906673082ff6c68149536fab3fb6311b6751eff543ad5b415861a7688a7
font_02_sfnt_off0000f50f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF50F 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230