Malicious PDF — malware analysis report

Static analysis result for SHA-256 6181a5c67aa65ac5…

MALICIOUS

PDF

77.1 KB Created: 2021-03-21 07:29:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: e99a4b3b3a021890c785c782784b4a16 SHA-1: 25f50dfee7b3239e9afa5affe3b02ab9a7664c0d SHA-256: 6181a5c67aa65ac59edd32da9073a7963ba04a958cf18a9937ca4475d5443719
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 ClamAV as a phishing trojan. The ML classifier also strongly indicates maliciousness. The document body, though heavily obfuscated, suggests a lure related to 'conjunction worksheets', which is likely a pretext to drive users to malicious sites like https://druttle.ru/123?utm_term=conjunction+worksheets+and+but+or+so for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://druttle.ru/123?utm_term=conjunction+worksheets+and+but+or+so PDF link annotation
    • http://nurigoluda.mygamesonline.org/28246519945.pdfIn PDF document text
    • http://bossyonlinex.com/tujalerewilaz010u1.pdfIn PDF document text
    • https://cdn.sqhk.co/madufuxenuw/hc8R3ED/pressure_washer_lowes.pdfIn PDF document text
    • http://sberbank.link/95535850009lkt0u.pdfIn PDF document text
    • https://cdn.sqhk.co/kezixowog/cHlbBjb/toca_hair_salon_3_gameplay.pdfIn PDF document text
    • https://cdn.sqhk.co/rejapugu/geu6jfY/didiwoxilinosovexete.pdfIn PDF document text
    • https://cdn.sqhk.co/nakizenonetu/prhbjcA/47374883581.pdfIn PDF document text
    • http://webmastervlad.ru/52757346142w2mit.pdfIn PDF document text
    • http://50offstore.pro/zopijemurilgpggu.pdfIn PDF document text
    • http://larokamexi.sportsontheweb.net/genesis_robert_alter_summary.pdfIn PDF document text
    • http://lnstagram-blue-ticks.com/931842443870kirs.pdfIn PDF document text
    • https://cdn.sqhk.co/wibononuve/hiicvgi/real_moto_brasil_jogo.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/be4b9a1a-56ec-4b42-842d-5aeda9368807/fefupamom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7290f3a1-0b5b-48b9-bda7-0564ce920df1/test_bank_for_financial_statement_analysis_and_valuation_5th_edition_by_easton.pdfIn PDF document text
    • https://s3.amazonaws.com/pukiza/pasim.pdfIn PDF document text
    • https://s3.amazonaws.com/tadevewuju/qradar_dsm_guide_7._3._1.pdfIn PDF document text
    • https://b01cffea-7a05-49e8-9781-04202a21c04b.filesusr.com/ugd/d5d855_2b35e3afb10648e292d3951445957815.pdf?index=trueIn PDF document text
    • http://giworutiw.myartsonline.com/ramemejufolubix.pdfIn PDF document text
    • https://s3.amazonaws.com/fumiposamisur/90160413202.pdfIn PDF document text
    • https://9e0ebcba-7e04-41ac-afc6-cfc574163c15.filesusr.com/ugd/6725b5_0a13d1ad6e3544a39506355a60eaa7b5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5854d269-e46c-497c-8df5-e81e3f830649/why_is_the_handmaids_tale_so_important.pdfIn PDF document text
    • https://s3.amazonaws.com/nilafafakem/janedab.pdfIn PDF document text
    • https://b9b086bb-db5c-4c47-b99c-4ca3d8c772c1.filesusr.com/ugd/c090b7_8adafbeb81fd482c9858cfe4a7482a73.pdf?index=trueIn PDF document text
    • https://6762652a-e869-40f3-960d-1446d4066230.filesusr.com/ugd/55e6b1_aea0e8a2eecb4e57ae587e77fb963dd8.pdf?index=trueIn PDF document text
    • https://38f9ccf9-db33-4582-994d-0ea518e52d38.filesusr.com/ugd/368de4_4c0e01278f5a4ad190a6a3735d5fce95.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/didowugorokirug/29303271472.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E7 5272 bytes
SHA-256: ce0551a0afb0b870a3d3539a9e6e83f0fdac3532fd37a0d7d160fa2b5cd54410
font_01_sfnt_off000102dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102DC 10276 bytes
SHA-256: 479d11f30566cc1b17bccc261c87712486733902902f6dd9ebe25a2016ad1f36