Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cd6688d152c3a6b…

MALICIOUS

PDF

67.8 KB Created: 2021-10-01 15:25:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d17bb96667a5e5a3089af3751f344513 SHA-1: 445b45745ec871b5ec4c378dfff20067cf649b55 SHA-256: 1cd6688d152c3a6b015c58958f6b0ee85fbed9a06d2240ef77a0f0da833c4e3d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. The presence of numerous external URIs, including one with a 'utm_term' parameter suggesting tracking, points towards a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the PDF structure and external links suggest it may leverage embedded JavaScript or other mechanisms to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://cructi.ru/uplcv?utm_term=video+editor+for+youtube+apk+mod PDF link annotation
    • http://asijskepotraviny.cz/files/file/nonitipixuzulinen.pdfIn PDF document text
    • http://t-cso.com/upload/file_folder/file/leziluferer.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/maxaja.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/88593203770.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/66398414412.pdfIn PDF document text
    • http://firewaterdamagedfw.com/test/fckeditor/uploadfiles/file/losegenegewikiti.pdfIn PDF document text
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/16815158674.pdfIn PDF document text
    • http://flomojapan.com/upload/files/riwalagewadixelazi.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/sagiwifo.pdfIn PDF document text
    • http://osoboebludo.com/ckfinder/userfiles/files/19577862207.pdfIn PDF document text
    • http://xn--80aaaghhaztbcd1agjgbccsgfftf.xn--p1ai/pict/file/35424607798.pdfIn PDF document text
    • http://preiswerte-unterkunft-papenburg.de/mediapool/dudorewinoger.pdfIn PDF document text
    • http://franceplus.fr/userfiles/file/35348303537.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/2021916347237138.pdfIn PDF document text
    • http://metamorfoza-krosno.pl/userfiles/file/kakiwoverosut.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/22103322037.pdfIn PDF document text
    • http://design-klasse.de/ckfinder/userfiles/files/61429506148.pdfIn PDF document text
    • https://netcsemege.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/jifurolinoti.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/pakovikazura.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/86986761412.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/fubezavikezidobofo.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/81441386075.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://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_off0000acd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACD7 14516 bytes
SHA-256: 92efb6ab5e2c7ed084e945acd49d7149f4270602599251fc0dc9bce4a950273e
font_01_sfnt_off0000d105.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD105 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e91c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91C 10756 bytes
SHA-256: f9b2f88d26d8dd626a1891312ba12517891442c486c3a0026abb06c993b06c56