Malicious PDF — malware analysis report

Static analysis result for SHA-256 628173c844eb73e8…

MALICIOUS

PDF

72.5 KB Created: 2021-03-13 19:27:05 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 00307bcf89438d064fa9dcdb8fb88279 SHA-1: 5ce38954f2762256808f4f464639fac2a66ae15f SHA-256: 628173c844eb73e8416d996a4f511ac3fc06a2ac9b3d45c8e535e1ee2cac8450
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File T1059.007 JavaScript

The PDF document contains heuristics indicating it is a link farm and a social engineering attack designed to trick users into downloading a converter. The embedded URLs, such as 'https://nipisod.ru/award?keyword=download+converter+pdf+to+word+nitro', are likely part of this lure. The ML classifier and ClamAV detection strongly suggest malicious intent, consistent with a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://nipisod.ru/award?keyword=download+converter+pdf+to+word+nitro PDF link annotation
    • http://creditreportfast.info/gawinorafijasinajxy7c.pdfIn PDF document text
    • http://minuduw.22web.org/76473629574.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488346/normal_5fd7b5e393b6e.pdfIn PDF document text
    • https://lafowujokunoro.weebly.com/uploads/1/3/0/7/130738997/209277.pdfIn PDF document text
    • http://grizhoff.ru/kutakesawefarofivurekeva71b.pdfIn PDF document text
    • http://badge-verification-center.com/51296735327erfku.pdfIn PDF document text
    • https://gutazalofekeva.weebly.com/uploads/1/3/5/3/135395177/fewefovakejaj_gumajavegobefi_zikumaloz_sadabojej.pdfIn PDF document text
    • http://dofujifeluradep.medianewsonline.com/why_did_mary_shelley_write_frankenstein.pdfIn PDF document text
    • http://popisazono.getenjoyment.net/teperetokefigetoxaxo.pdfIn PDF document text
    • http://vexasefagi.scienceontheweb.net/latex_beamer_insert.pdfIn PDF document text
    • http://pshcomonhere.xyz/lg_refresh_rate_50hz14gzg.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374951/normal_5fe11d1285eb8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385424/normal_6004e09c83f5c.pdfIn PDF document text
    • http://badgesverified.com/humboldt_county_sheriff_police_reportsz89cd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://23da7c74-6e14-424a-b22a-901aa35eafb1.filesusr.com/ugd/9cc572_98fa18469aab49e69695c9541eb2120b.pdf?index=trueIn PDF document text
    • https://368051e9-4199-40ea-b9a2-dc6e6f83cb3b.filesusr.com/ugd/6260fe_6234da40ac014924b728a9d03abf551d.pdf?index=trueIn PDF document text
    • http://palexibibiw.atwebpages.com/quadratic_equations_problems_and_answers.pdfIn PDF document text
    • https://c827806f-f9bf-4fd3-a4ce-e487c020fa79.filesusr.com/ugd/6fd45c_db51c8fb1c4f4021a970e5fd58ca2db6.pdf?index=trueIn PDF document text
    • https://f38be386-5799-403b-9303-fb121113655a.filesusr.com/ugd/6f1aa7_80c3868d1762406aaaaba221f2bcf963.pdf?index=trueIn PDF document text
    • http://vezuzatutuxi.epizy.com/baghban_movie_3gp.pdfIn PDF document text
    • http://zipokuxabatu.rf.gd/gidakexemenobipabojitij.pdfIn PDF document text
    • http://tinijev.epizy.com/xatasopofiwuni.pdfIn PDF document text
    • http://fojodopid.rf.gd/kaxonepugovitamuwakifaxi.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_off0000de39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE39 5120 bytes
SHA-256: 162840dfc72c5ffd763a900958a4c0253249992a80df68a5ed3e125e31ba34a6
font_01_sfnt_off0000efd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD9 10860 bytes
SHA-256: e9c6f74f6f7ae1fe1feaa62ad445878363958d39808db15bd22810502f1afd1c