Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa2fbd5d22dddc7a…

MALICIOUS

PDF

81.1 KB Created: 2021-04-04 10:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cd9fb288e30b8c4b212fc7596c476a90 SHA-1: 9b5723fe3e92f37fed916706c4fcecb5d65b444a SHA-256: aa2fbd5d22dddc7a2a617850f19586f3e30b9b4f8f46fab6ed2b34aa4e4d39a0
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The primary malicious URL identified is https://dafemum.ru/strik, which is likely used to redirect users to further malicious content or download payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • 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
  • 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://dafemum.ru/strik?utm_term=quotes+from+one+of+us+is+lying+with+page+numbers
    • https://cdn-cms.f-static.net/uploads/4425235/normal_6044fb3dee125.pdf
    • https://cdn-cms.f-static.net/uploads/4385859/normal_6035282708fad.pdf
    • https://static.s123-cdn-static.com/uploads/4382790/normal_5ff8ca5663c84.pdf
    • https://static.s123-cdn-static.com/uploads/4417212/normal_5fcc7e996950b.pdf
    • https://cdn.sqhk.co/nadizolobe/chgjd1b/orange_nasa_hoodie_target.pdf
    • https://cdn.sqhk.co/zikufivol/huvWVhj/remibaragufisud.pdf
    • https://cdn.sqhk.co/lewiwifo/jigupKV/42869999646.pdf
    • https://cdn.sqhk.co/sevigexew/jjaific/facebook_lite_messenger_for_iphone.pdf
    • http://zakofim.iblogger.org/45078649297.pdf
    • https://cdn.sqhk.co/pewesopefim/xjh69rJ/does_plinko_master_let_you_cash_out.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://7737876a-f762-42ef-af6f-18b78abacabf.filesusr.com/ugd/9066bd_3a23955312a341eeb1d2525c2d8a774f.pdf?index=true
    • https://1ac5d900-0c69-4f12-8b1d-4e209472b8d2.filesusr.com/ugd/828753_ef3af3bf319b4141b4fd1527b6ef868f.pdf?index=true
    • https://fa5d8e44-005d-4c05-925d-ba60cb7f5023.filesusr.com/ugd/121e37_6d4ab17f4ef4443c8ad922663e74c314.pdf?index=true
    • https://05efeaee-ea5b-4dc8-bddc-a5098cc0dcbd.filesusr.com/ugd/c06c30_84db68f555ab43989e75b27b1d1e4e81.pdf?index=true
    • https://4cd5eafb-d261-4666-a528-29b55b1676c1.filesusr.com/ugd/8dde66_2aae78f48f9d449f9819bc077b6fc418.pdf?index=true
    • https://b1e6e3cd-24a2-426a-8b7d-e8f4bd81915b.filesusr.com/ugd/83e584_1fb048910794473abdcf8b297d507e5d.pdf?index=true
    • http://tezezilomaxa.epizy.com/42494045515.pdf
    • https://72a23b54-95c1-47c0-80d6-f7b1310faeb8.filesusr.com/ugd/65b209_41f1df66c77242c4ae2fa626392b2c91.pdf?index=true
    • https://76b44699-1094-4fd8-8d4a-70b7be8159c3.filesusr.com/ugd/c450b2_b476d5b1d5594b499aba3c21eb389fda.pdf?index=true
    • http://lenaxepejo.rf.gd/mandera_county_bursary_form_2020.pdf
    • https://b81e1767-bb0d-4562-9f98-cfef66859bb1.filesusr.com/ugd/b48b60_5454c02653564a72b53da09d5ad8b5d7.pdf?index=true
    • https://86a9da1b-0b57-4b35-a77a-523886b904cd.filesusr.com/ugd/0d9a50_53d63a2f0f9445caaaf79ca7b83fab85.pdf?index=true
    • https://e4da1597-3bb3-488b-9226-7c2c9e06e9ce.filesusr.com/ugd/db5d73_5cd95ac9104f47e0b7962ebf27c0d28b.pdf?index=true
    • https://e8e87dc5-637d-47ba-9de6-e7d98d123d78.filesusr.com/ugd/a69a03_edeee2434d9447cd8bbc07840c288870.pdf?index=true
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecd9.bin
66234d621fbb88363c56c62f0fb9168f65bb5f4cb205c130223b3753f56dbbd3
pdf-font-stream PDF embedded font (sfnt) at offset 0xECD9 5592 bytes
font_01_sfnt_off0000ffc0.bin
4265a1e0eadd81911b719507ae062e405d93d6ef98dbc47ffd8c578a110e1c6d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC0 11724 bytes
font_02_sfnt_off000126cc.bin
9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x126CC 4324 bytes