Malicious PDF — malware analysis report

Static analysis result for SHA-256 83a4af2df95ffd6b…

MALICIOUS

PDF

85.7 KB Created: 2021-03-29 16:17:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 0344848dc1c171a22d8c2884d02d8c32 SHA-1: 2778f88899e78ccaae3a95a97f2290850b36c27d SHA-256: 83a4af2df95ffd6b370e4334eb42c2e7a36af3617bc8deb265c3c08a3beb9be5
126 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary malicious URL identified is https://xajibur.ru/wix?keyword=ap+human+geography+unit+2+study+guide+answer+key, which is presented as a study guide answer key to entice users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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
  • 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://xajibur.ru/wix?keyword=ap+human+geography+unit+2+study+guide+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4408172/normal_603b5aebc1c3d.pdfIn PDF document text
    • http://giwudogor.scienceontheweb.net/atal_pension_yojana_details.pdfIn PDF document text
    • https://cdn.sqhk.co/nejijilo/dcwTPZa/95252272648.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481417/normal_5ff7682a17263.pdfIn PDF document text
    • https://cdn.sqhk.co/dunuxorigu/TVZjbhe/android_box_4k_mxq_pro.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387698/normal_6055621d5350e.pdfIn PDF document text
    • http://dupigetibulira.iblogger.org/carry_on_jatta_movie_free_mp4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444622/normal_602d0bff47801.pdfIn PDF document text
    • http://pazifelurup.medianewsonline.com/recette_de_cuisine_algrienne_gratuit.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/900f5a61-8b84-4210-baf7-53244f1c00c4/how_to_score_reading_comprehension_on_ktea_3.pdfIn PDF document text
    • http://gasukexopesifu.epizy.com/calculus_early_transcendentals_solutions_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/47681d4f-b985-4719-b099-0c4bfd6a7b5e/whitfield_pellet_stove_serial_number_location.pdfIn PDF document text
    • http://wepuwuzuvam.epizy.com/bodybuilding_exercises_with_pictures.pdfIn PDF document text
    • http://dodujorumapide.epizy.com/xidumiv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a0badcc-a106-46e3-8de6-465caa90118c/56416515046.pdfIn PDF document text
    • http://wumurunapaxilar.rf.gd/bebapeberezixuraki.pdfIn PDF document text
    • http://favagapararo.epizy.com/american_authors_believer_free.pdfIn PDF document text
    • http://sunulenebesug.rf.gd/31756901292.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a1f8ff4-99c4-4d19-b65e-ed201900fbfa/73718073450.pdfIn PDF document text
    • http://rorazizaxaf.atwebpages.com/gunelepisop.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7912c246-8485-4ae7-990f-009bd27c67e3/kulojanoxagemerina.pdfIn PDF document text
    • http://jagogapibibolin.epizy.com/wopodekomurumuwe.pdfIn PDF document text
    • http://wivifizurata.epizy.com/67453556655.pdfIn PDF document text
    • http://repafow.epizy.com/fepunubanoxosubujopawuba.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA3F 5720 bytes
SHA-256: 57828dc475599fbbe53d19ce2a1aee6bd248b1d37f1cb7a2236f5b3611f03e5e
font_01_sfnt_off00010da9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA9 11028 bytes
SHA-256: 6aa8d6887ebb54ce4951855076998cba196006a0d3a9ba8265496a9c52c142ef
font_02_sfnt_off00013381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13381 16116 bytes
SHA-256: f8e326b96df6c0457890c6346fd7f60b91beb129051a642dbd03fdf119a21fd7