Malicious PDF — malware analysis report

Static analysis result for SHA-256 639c6e56b4d68239…

MALICIOUS

PDF

82.2 KB Created: 2021-05-24 10:49:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 11f1bd5b177f44f160ef099b9c94b97c SHA-1: 52373563e1e4857d65898af0ff4f779e64e5fffd SHA-256: 639c6e56b4d6823910837267cbab59498e732cb2a57dd3ef019c167530dd2990
194 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics and a machine learning classifier, specifically flagging it as a PDF redirector link to a known malicious domain. The embedded URL, 'https://dafemum.ru/strik?utm_term=delf+prim+a1+syllabus+pdf', is the primary indicator of malicious intent, likely serving as a lure for phishing or to download further malicious content. ClamAV also detected it as 'Pdf.Phishing.Trojan'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://dafemum.ru/strik?utm_term=delf+prim+a1+syllabus+pdf In PDF document text
    • https://static.s123-cdn-static.com/uploads/4426972/normal_5fc67b6671a78.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416299/normal_5ffd26107b850.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414847/normal_5fe45459005fd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378382/normal_60446ae165d30.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416927/normal_5fdb989792f62.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393763/normal_604b280a957cf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462374/normal_600c97f698023.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463830/normal_604dd83788df3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382627/normal_5fddc0a65af14.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382958/normal_6058331d2ee2b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485939/normal_60159bfb7c93e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497369/normal_6067ec0ae6867.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417046/normal_6011d50817ae8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460688/normal_6029b094aeac9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471253/normal_60609681c1c73.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4482869/normal_5ff3fd5a3e97b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500679/normal_605877e3e593a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387924/normal_6024f148845a8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4497372/normal_5ff40c3956064.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461751/normal_5fe2c5934b542.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/pujinit/reply_and_defence_to_counterclaim_template.pdfIn PDF document text
    • https://s3.amazonaws.com/xajowu/famuxabizoresuv.pdfIn PDF document text
    • https://s3.amazonaws.com/vitelitubovuluj/15647938710.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_off0000f2c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C0 5064 bytes
SHA-256: d16fb17b35776e7a76a773f25dfb969353aeff1df43867bb40dc58fccbe14226
font_01_sfnt_off000103f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103F4 11992 bytes
SHA-256: 69a7b8f9aacc435867febe35c837095cb7e8f6c34cc7ba20f692bcfc00967f9e
font_02_sfnt_off00012bbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BBE 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378