Malicious PDF — malware analysis report

Static analysis result for SHA-256 33670d1ffc1bd754…

MALICIOUS

PDF

82.6 KB Created: 2021-03-15 16:39:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 7ea5e7f8f4f30647a6fb3ab2f23a373e SHA-1: fd45e380a7013523936235a8bdc535f7ea33643a SHA-256: 33670d1ffc1bd75432193e2fec026ad8ee87547ec7b8a2a8e66aa9525855ab85
184 Risk Score

Malware Insights

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

The PDF contains multiple embedded links pointing to suspicious domains, with one specifically identified as a known malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to a 'heat exchanger calculator', likely to trick users into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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/aws?utm_term=heat+exchanger+calculator In PDF document text
    • http://kapovulup.mywebcommunity.org/13560291889.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368240/normal_6032ae63015d4.pdfIn PDF document text
    • http://thesalle.xyz/what_does_the_bible_say_about_good_characterpd2ik.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392193/normal_602b969cbf9f2.pdfIn PDF document text
    • http://wotaxatumumodok.sportsontheweb.net/willingness_definition.pdfIn PDF document text
    • http://lumacy.site/55917778299npuk.pdfIn PDF document text
    • http://lotibamuzuti.scienceontheweb.net/hypospadias_et_epispadias.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384822/normal_6045130a3c84a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369935/normal_5fccfc08ec03d.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://xonolori.atwebpages.com/konadisazux.pdfIn PDF document text
    • https://s3.amazonaws.com/xonaxevetaf/viper_alarm_ezsdei474v_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09915220-b276-438b-9e2f-3c93972a8d66/80869253300.pdfIn PDF document text
    • https://s3.amazonaws.com/sakaburepagase/lodapewig.pdfIn PDF document text
    • https://s3.amazonaws.com/tetenifeme/article_writing_jobs_in_pakistan_online.pdfIn PDF document text
    • http://zirutabu.myartsonline.com/detowakezowepotesir.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b3f8959-a0f8-472b-971c-98a3cbd905e8/maytag_dishwasher_error_codes_e1_f9.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f5da070d-b085-4757-ad4c-f5437ac9b43b/xexolonokajuwukobewavewoj.pdfIn PDF document text
    • https://s3.amazonaws.com/roware/84091394910.pdfIn PDF document text
    • http://nabulegewuwal.myartsonline.com/calculus_on_manifolds_spivak.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e4986b6-0535-4a55-9499-3d4eed610539/10623448466.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/915e5239-5de2-4deb-b620-fe8ccac29588/25022723311.pdfIn PDF document text
    • http://kijonag.onlinewebshop.net/italo_calvino_complete_cosmicomics.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_off0000f6b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B7 4744 bytes
SHA-256: 5d42019accea0b7292e52fdc827acc496608b6e446970fd90416ae4a1300ff9c
font_01_sfnt_off000106c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C8 12088 bytes
SHA-256: 0aaa9d0ce0dcbdccc410c91ace0af03d4c63b67e1b116a9dd98afc55eb2c40b4
font_02_sfnt_off00012e82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E82 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c