Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c5f3fae06c61f9…

MALICIOUS

PDF

74.7 KB Created: 2021-09-16 04:23:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a2fadabdedf7b2380b16f22e4f41e839 SHA-1: b367b4968995c8703ce264364acdcfc5900db990 SHA-256: f4c5f3fae06c61f9e4d39f7efcc5c99ae0dd3a0fcd9ac4cc1e8319852b645f18
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to link farms hosted on disposable domains, a common tactic for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or trojan delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ketchas.ru/uplcv?utm_term=download+picsart+pro+apk+free PDF link annotation
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/45034756720.pdfIn PDF document text
    • http://melvin.cz/data/57281097666.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/mikabanizodaxuponu.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/kodurezibofuwizax.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zukapiwonikopajozimova.pdfIn PDF document text
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/90545253194.pdfIn PDF document text
    • http://papierplus.pl/userfiles/file/lubesoxuverikigukowu.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136a929c0e95---majexugurovujasi.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/95762849533.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/46528305000.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613345b2aaa3a---40297195030.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/50912174712.pdfIn PDF document text
    • http://tehla.eu/userfiles/file/96635798458.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/90349304959.pdfIn PDF document text
    • http://drzwiukryte.pl/userfiles/file/nutogugikufelunoporezame.pdfIn PDF document text
    • http://vivaldiskibus.com/FileData/ckfinder/files/20210916_D15B979F7DD453D2.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/pepipuwom.pdfIn PDF document text
    • http://teacherandtraining.com/coj_u/KK/userfiles/files/46420314812.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/4835272600.pdfIn PDF document text
    • http://hoya889.com/upfile/files/20210903225118.pdfIn PDF document text
    • http://5percent-design-action.com/upload/users/files/66936221090.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_off0000c2a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dabd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABD 10792 bytes
SHA-256: 6fefdc1845756d4c01a4d467eb616adf4abb124623c5c4dc8caaa6fa7ed3f9bb
font_02_sfnt_off0000f3c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C6 16260 bytes
SHA-256: 994517348e987520e70296ca070f5769b9c3b163f53de2b4a50bf7afd7400984