Malicious PDF — malware analysis report

Static analysis result for SHA-256 335a9a06e373ea15…

MALICIOUS

PDF

90.9 KB Created: 2021-09-10 15:59:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 273a8b85825241eb4d77cf092fd46d7e SHA-1: 7f664fd6167dee1cc84b52935e166a8cc4521b34 SHA-256: 335a9a06e373ea151a81e9f697388ed86f021ae21e48fbcd5eabd88d23d754f0
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to disposable domains. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates the document likely instructs the user to decrypt a password-protected archive, a common tactic for evading gateway security. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://cructi.ru/uplcv?utm_term=turn+phone+into+wifi+repeater PDF link annotation
    • http://changwontour.kr/FileData/ckfinder/files/20210907_0F6E510131A40DE2.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-8/20210908175302676653.pdfIn PDF document text
    • https://syteq-pro.com/userfiles/file/47299962611.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/48948064010.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/25101327343.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/40405293078.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/65904172974.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/52317613769.pdfIn PDF document text
    • http://exteractif.fr/pictures/2/kokuf.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210904204846.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb788b266---642151018.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/54726537508.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/71873957881.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/neselaxujunimudip.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/7663735873.pdfIn PDF document text
    • http://orthodoxnews.us/file/tufagexamupul.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/96631665700.pdfIn PDF document text
    • https://jucariicopilasi.ro/app/webroot/files/userfiles/files/23968820023.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/285a282c7d2e86b56113d2afc7a379bd/jiledinikobasedif.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/72146583206.pdfIn PDF document text
    • https://sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/27952850799.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE212 19376 bytes
SHA-256: cbd58dced92ad37cc248ed598c1c1b3e0cdd1b44a9617ff5a2cf1919a2c63e7a
font_01_sfnt_off0001126f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1126F 18172 bytes
SHA-256: 262b419de96b0cc407d9d0985712d1c49250dfdf04ad45e38b515124ac0c70ff
font_02_sfnt_off00012e8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E8A 10388 bytes
SHA-256: 238b48676ea4b7219f0ad477c7f9dcca0173666fb4d280b168f3ebcd2ece7f9a
font_03_sfnt_off00014607.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14607 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1