Malicious PDF — malware analysis report

Static analysis result for SHA-256 64cbadf42e8106ef…

MALICIOUS

PDF

80.3 KB Created: 2021-05-18 14:45:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 840bbc04df683833cb3990e021ae3f44 SHA-1: bb61bc48f26732ea583ca0cbf88b4aeae1646dc8 SHA-256: 64cbadf42e8106eff00966325989157c632c9434aad6277f85bf10fdcd6ea9cd
254 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many of which point to redirectors and SEO link farms, indicating a phishing or malware distribution scheme. The heuristic 'PDF_MALICIOUS_REDIRECTOR_LINK' and 'PDF_SEO_LINK_FARM' strongly suggest this intent. The primary malicious URL identified is 'https://yafferge.ru/strik?utm_term=math+book+6th+grade+answers', which is likely used to deliver a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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
  • 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.
  • 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.
  • 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://yafferge.ru/strik?utm_term=math+book+6th+grade+answers In PDF document text
    • https://cdn-cms.f-static.net/uploads/4483354/normal_60656f7c4dab9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415944/normal_600d144823594.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387242/normal_600f2e0eee463.pdfIn PDF document text
    • https://jaxifojuw.weebly.com/uploads/1/3/5/3/135351184/4703c201.pdfIn PDF document text
    • http://tesapewuj.22web.org/boxebivukidapakafiv.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502493/normal_606b70e316f91.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427785/normal_6001306010940.pdfIn PDF document text
    • http://gadolokelijibus.iblogger.org/highest_paid_jobs_in_computer_science.pdfIn PDF document text
    • https://lefamadagizid.weebly.com/uploads/1/3/4/7/134704745/keferezovekadi_molixazeguja.pdfIn PDF document text
    • https://limowidijepa.weebly.com/uploads/1/3/5/9/135992559/f4e18968d.pdfIn PDF document text
    • https://gukabezifom.weebly.com/uploads/1/3/6/0/136051166/2253122.pdfIn PDF document text
    • http://vulifux.66ghz.com/battle_royale_song.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
    • http://mawabubobiniz.rf.gd/61431023649.pdfIn PDF document text
    • http://riwuzapivegeb.rf.gd/xisoluredoniwusawoperaxa.pdfIn PDF document text
    • http://nimukefamax.rf.gd/42260226041.pdfIn PDF document text
    • https://s3.amazonaws.com/pasawexawinogad/what_is_the_best_indoor_home_security_camera.pdfIn PDF document text
    • https://s3.amazonaws.com/wujapu/jmi_acknowledgement_slip.pdfIn PDF document text
    • https://s3.amazonaws.com/wanasuvedigo/puwofolume.pdfIn PDF document text
    • https://s3.amazonaws.com/fujadabez/piwofuk.pdfIn PDF document text
    • https://s3.amazonaws.com/wobuzisibal/rapedabupigadi.pdfIn PDF document text
    • https://s3.amazonaws.com/jaloto/vejositifobino.pdfIn PDF document text
    • http://dapolejalufimi.rf.gd/spring_jmstemplate_message_selector_example.pdfIn PDF document text
    • https://s3.amazonaws.com/zuwimadaneb/exterior_angle_theorem_maze_solving_equations_answers.pdfIn PDF document text
    • http://kifinuneniw.rf.gd/xowijuto.pdfIn PDF document text
    • https://s3.amazonaws.com/falufusu/75483252602.pdfIn PDF document text
    • https://s3.amazonaws.com/vavejijitatofu/ford_focus_1.6_2003_engine_oil.pdfIn PDF document text
    • http://loruluze.epizy.com/icloud_login_android_phone.pdfIn PDF document text
    • http://nuxiluruzijova.epizy.com/ctet_paper_1_syllabus_in_english.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_off0000eec9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC9 5248 bytes
SHA-256: c65227de226558bdc094bae9808fdc9a5ab50c473bf08a686bd49e58dcf04711
font_01_sfnt_off000100a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A9 10644 bytes
SHA-256: 8619e3934dabbd80efea7f654379d4710c1a8bb2e9a5baf8c68c43d9a568e1ab
font_02_sfnt_off00012521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12521 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2