Malicious PDF — malware analysis report

Static analysis result for SHA-256 75e81c9334893066…

MALICIOUS

PDF

86.2 KB Created: 2021-03-28 07:34:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: fec667652a264512025da210f02009a1 SHA-1: 21050c8e8e62b14923ab10186b8679ecc6ac63ce SHA-256: 75e81c9334893066a664f54fb23d91bdae9ef70177c86bfb659d9a818c4a64f2
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged by heuristics as a link farm designed for SEO manipulation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via the primary URL: https://vilenefex.ru/strik?utm_term=which+course+is+best+for+english+teacher. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://vilenefex.ru/strik?utm_term=which+course+is+best+for+english+teacher PDF link annotation
    • http://lojapidabud.mypressonline.com/dotutelonezabuzem.pdfIn PDF document text
    • http://kigalasabipigo.medianewsonline.com/fevavorejofod.pdfIn PDF document text
    • https://cdn.sqhk.co/luzorisu/RcjaJgd/superstar_hair_salon_mississauga.pdfIn PDF document text
    • http://sqrab.top/varekoxonutamepezivp8dtm.pdfIn PDF document text
    • https://cdn.sqhk.co/xuwolupenilu/aJjezPn/iphone_4_cydia_apps_free.pdfIn PDF document text
    • https://cdn.sqhk.co/wugeguxu/gwjmDHy/tuvid.pdfIn PDF document text
    • http://instofficial.online/13819622165zi1nz.pdfIn PDF document text
    • http://pristav.pro/3182663057283gu5.pdfIn PDF document text
    • https://cdn.sqhk.co/derilalovate/dajcFgh/tic_tac_toe_family_game_board.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463002/normal_6015ff3b15a6a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384649/normal_600a2778a4258.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://37e0f79d-b0c1-4727-b76d-5b759c81288f.filesusr.com/ugd/9c66ff_5c643ba8350a4f208be18e2e9c37e7e8.pdf?index=trueIn PDF document text
    • https://ea74ff18-003d-4094-8454-8d7e15e33abb.filesusr.com/ugd/50de67_ef4052df4ce1455c983249d505b02266.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7ef3449d-1fb2-4377-98e1-994f701831d1/xotulusof.pdfIn PDF document text
    • https://3c3b6f52-20a2-448a-be11-eec5930c502f.filesusr.com/ugd/0ca786_8d3bbd612e1d4eb692ec03a0ad46c18d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/53f39f39-e77d-40d5-9b15-b7612113a51f/algebra_with_pizzazz_answer_key_page_65.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/56843d45-a710-486a-8461-b1d9ba38ab9e/safety_siren_pro_series_3_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8f8aada4-7aed-4fd5-ba46-63375b591514/harbor_breeze_merrimack_ii_52-in.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4655baa3-7b9e-4836-ae6e-5fa4aadf95e0/sekinubugosezor.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF37 5180 bytes
SHA-256: 47c950ae510d8c1ca75820459d495f2bf4f8ab3cbd7c54bec1825f38d5ddda5f
font_01_sfnt_off000100d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D7 11448 bytes
SHA-256: 7d8c8a3d71143f1c06f0fb5c9731449d62a218e4af58885f19492feac62e9c24
font_02_sfnt_off00012799.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12799 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd
font_03_sfnt_off00013cc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CC6 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f