Malicious PDF — malware analysis report

Static analysis result for SHA-256 af20c6fa6b039c36…

MALICIOUS

PDF

71.0 KB Created: 2021-09-30 19:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5d5082bae62ee4fbfe1ef251848df52f SHA-1: 65d634be1cb52b72cacc151437cb8553c5ee2388 SHA-256: af20c6fa6b039c360bdcb956d0bc5cd36f053020d6875ed4c6026c5b6ed7daf9
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as a malicious PDF by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external URIs pointing to disposable domains, indicating a link farm designed for phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, noting the use of disposable hosting and UTM parameters.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://irlanc.ru/uplcv?utm_term=too+hot+to+handle+online+free PDF link annotation
    • https://ensegun2.com/ckfinder/userfiles/files/44463627237.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/7eb4ba5705928e424b567395037112ab/semoxok.pdfIn PDF document text
    • http://sichera.eu/userfiles/files/revarugejonudisidimuvonar.pdfIn PDF document text
    • http://nanopena.cz/upload/file/didelutoxeje.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/wowadan.pdfIn PDF document text
    • http://centromp.it/userfiles/files/zanerozeweroragas.pdfIn PDF document text
    • https://promoxcenter.ro/ckfinder/userfiles/files/wudupimegezediwimo.pdfIn PDF document text
    • http://whatifitspossible.com/ckfinder/userfiles/files/tujugekabusaxejuvisakabos.pdfIn PDF document text
    • https://hogozaty.com/ckfinder/userfiles/files/34367633240.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/jepanaguwixumudes.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/fb3785f7a65d4347ef82bb3775d82096/56320649961.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/83035668726.pdfIn PDF document text
    • https://chasehr.in/userfiles/file/49649250190.pdfIn PDF document text
    • http://artkulinaria.pl/sites/default/files/file/gasalopebufisa.pdfIn PDF document text
    • http://plovdivweek.com/app/templates/js/ckfinder/userfiles/files/88949822816.pdfIn PDF document text
    • http://gonvvama.net/filespath/files/20210901122050.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/vetefitulogekesilasi.pdfIn PDF document text
    • https://spcinternational.in/ckfinder/userfiles/files/pibobusovolatiguzokoku.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/58576569063.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/53760599023.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/xidevexoranub.pdfIn PDF document text
    • http://alhegazgroup.com/userfiles/file/kuzasovufitoz.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/40709769732.pdfIn PDF document text
    • http://aguito.madteam.net/ckfinder/userfiles/files/24324266612.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_off0000b293.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB293 10248 bytes
SHA-256: f55aea87a60808c40a395f01649a03a27ef7b6cf3ee7f8a2464bd322801661b7
font_01_sfnt_off0000c973.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC973 17492 bytes
SHA-256: 2ebf797382c249aaa6c6370597a9b3a5325a2b81ae88b3867e2db8da5d0dc8c4
font_02_sfnt_off0000f64d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF64D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1