Malicious PDF — malware analysis report

Static analysis result for SHA-256 257c0a1bc515961e…

MALICIOUS

PDF

70.2 KB Created: 2021-03-20 21:43:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: a6533bd42f8ca221c5c3973c2bc3c60d SHA-1: c6dd9843b89f5d1418b40f467a0c2b20cb4c1936 SHA-256: 257c0a1bc515961e9d83b66ea4c0177920385db552dc3b214d701fd29124208e
184 Risk Score

Malware Insights

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

This PDF file contains numerous embedded links, many of which point to disposable hosting domains and known malicious redirectors. The primary lure appears to be related to unpacking APK files or providing other content, as indicated by the URL parameters and heuristic firings. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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.
  • 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.
  • 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/wix?keyword=unpack+apk+apktool In PDF document text
    • http://wijutomotagam.mypressonline.com/lewilunolijusosonow.pdfIn PDF document text
    • http://jaxifas.getenjoyment.net/73122803151.pdfIn PDF document text
    • http://kotudekudoges.getenjoyment.net/conflict_resolution_worksheets_for_middle_school.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448357/normal_6033b8dbb432a.pdfIn PDF document text
    • http://dapurixid.sportsontheweb.net/august_2020_current_affairs_gujarati.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476596/normal_5fca3cee7b91a.pdfIn PDF document text
    • http://lofajemami.sportsontheweb.net/visual_basic_reserved_words_list.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372104/normal_602762a42fa33.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494433/normal_5fc739e585353.pdfIn PDF document text
    • http://devubowoku.mypressonline.com/barber_adagio_for_strings_piano.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425009/normal_601e0c6608b20.pdfIn PDF document text
    • http://sewukagazub.mypressonline.com/how_to_identify_black_walnut_in_winter.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454052/normal_60128d2719b01.pdfIn PDF document text
    • http://suzofovolavuk.scienceontheweb.net/debiwobuvokazozarage.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453900/normal_60112c7d7bd6b.pdfIn PDF document text
    • http://tigafik.mygamesonline.org/zananupinomam.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4389085/normal_5fcc8f3b94117.pdfIn PDF document text
    • http://werikipirojenob.scienceontheweb.net/bible_commentary_books.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://koduwutuvage.onlinewebshop.net/durexaf.pdfIn PDF document text
    • https://b84c3727-5d5a-4c5d-9d5d-21cac87b3a69.filesusr.com/ugd/fdd6c2_1162dfa1d19b42faae9fe852eaf11993.pdf?index=trueIn PDF document text
    • https://a91873a8-1f5b-4151-915d-af39eb211f25.filesusr.com/ugd/3f80ec_ee6b55908aed46a9bf10a8a45fa163f9.pdf?index=trueIn PDF document text
    • https://83d12552-0bc1-4415-b221-1da25caacb9b.filesusr.com/ugd/1e11d0_e08716e9ce2344fd89d3724211086a62.pdf?index=trueIn PDF document text
    • http://tipipigi.atwebpages.com/kogaf.pdfIn PDF document text
    • http://schemas.android.com/apk/res/android���package���platformBuildVersionCode���platformBuildVersionName���manifest���brut.apktool.testapp���1.0���21���APKTOOL���In 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EB 4708 bytes
SHA-256: 76f232cb547d5b8bee708c5775408db69e8b964b88961fd2d7f1422cd1f73a0d
font_01_sfnt_off0000e70e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE70E 10940 bytes
SHA-256: 5c4c5b22a63f2602c9e7ca6943e72e2f67aebd28a914cc8adbb236804c7f4edd