Malicious PDF — malware analysis report

Static analysis result for SHA-256 c28fa42a664cde46…

MALICIOUS

PDF

87.2 KB Created: 2021-04-05 14:15:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: fe74d3be441b80209dcda787436f8074 SHA-1: c5d94a64cf4378c68d5021f6a00defd682ffb531 SHA-256: c28fa42a664cde46012bbcb4ae35a3fe8d0b8923c5d705e5a89b926aa2224ef7
126 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to link farms hosted on disposable domains, suggesting an attempt to redirect users to malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates a link farm on disposable hosting, and the presence of external URIs further supports this. While no scripts were explicitly extracted, the PDF structure and numerous URLs point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://ponafet.ru/wix?keyword=factorizacion+de+binomios+definicion PDF link annotation
    • http://espaceabonnes.com/719049089spilw.pdfIn PDF document text
    • http://getveran.site/is_brother_printer_airprint_enabledzf8b9.pdfIn PDF document text
    • http://top-odejda.com/80600139650o5610.pdfIn PDF document text
    • http://film123watch.com/dd_3.5_mago_buildwmb8x.pdfIn PDF document text
    • http://wodedutipif.medianewsonline.com/59370597206.pdfIn PDF document text
    • http://urott-hu.com/how_to_tell_if_a_penny_stock_is_good7s099.pdfIn PDF document text
    • http://xadimilok.iblogger.org/histology_guide_university_of_leeds.pdfIn PDF document text
    • http://bifugejif.22web.org/in_my_father_s_house_kwame_anthony_appiah.pdfIn PDF document text
    • http://lnstagramverifiedbadge-form.com/bloons_tower_defence_5_towers_guidepsk8m.pdfIn PDF document text
    • http://mateguwokalidub.getenjoyment.net/runotepopeguguluful.pdfIn PDF document text
    • http://save50.pro/what_are_the_major_factors_that_affect_climate1123c.pdfIn PDF document text
    • http://bbflowers.net/a_thousand_splendid_suns_audiobook_youtubemz1o4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xuxerutiwuv.onlinewebshop.net/kumabojamonivipafusijuw.pdfIn PDF document text
    • https://s3.amazonaws.com/zunewidimem/96566395043.pdfIn PDF document text
    • http://vegusofeta.rf.gd/widopadeza.pdfIn PDF document text
    • http://joriboka.epizy.com/67041892435.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e6cdaf95-ed00-47d8-a4aa-2ff4bb4565e3/echo_cs_400_chain_size.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/77a862e1-e71b-4d29-86f9-e07ae45a47e8/20322633543.pdfIn PDF document text
    • https://s3.amazonaws.com/dazuxujepov/french_a2_vocabulary_list.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15b7bec1-73ad-4f66-9a1b-066afdd8c63e/fujibulip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/060a46bf-e263-4d05-9dd1-5a2bcb9492a0/jimaladusozelefid.pdfIn PDF document text
    • https://s3.amazonaws.com/vaxebisapesi/bacillus_fusiformis_disease.pdfIn PDF document text
    • http://soxenaroguz.rf.gd/annamalaiyar_songs_isaimini.pdfIn PDF document text
    • http://zaxuzut.atwebpages.com/amadeus_gds_training.pdfIn PDF document text
    • http://vedixemalirugi.atwebpages.com/bivuna.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_off0000fb56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB56 5280 bytes
SHA-256: 3c8d6e2b469bd433582eb8832951a128895f6edcbcbbd2ba21af4c8f4c0cf020
font_01_sfnt_off00010d3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3B 12968 bytes
SHA-256: 353ac770186a621541496c336b32e57c61037611c8c8242de4435cb7bf1641b4
font_02_sfnt_off000137f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137F2 16152 bytes
SHA-256: cbc13509c5fcb0fb09f761580c2a5686ca662c90df46a338a6dfc62d15a097e3