Malicious PDF — malware analysis report

Static analysis result for SHA-256 2518610c3807bae2…

MALICIOUS

PDF

68.6 KB Created: 2021-10-01 14:30:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c4037a01111fcf58ec17cf87a2048b66 SHA-1: 9f4f2518fde68ebb63acb1a27f408aef580f61a1 SHA-256: 2518610c3807bae2b001404ff42f63a2f050b5c1baf0210c840301bdd549662c
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan. It contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the presence of multiple external URLs suggests an intent to redirect the user to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=chicago+mass+choir+hold+to+god%27s+unchanging+hand PDF link annotation
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/54504725082.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/43581290049.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/busejotonogapabugised.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/3f122b93f2df6a6ac6239e7dd40b8291/radolezixuzokobujepekujor.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/fixoz.pdfIn PDF document text
    • https://millvalley.com/wysiwygfiles/file/galebigotojenetalabelar.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/wupovofeni.pdfIn PDF document text
    • https://doctornhospital.com/banglanews24/editorsfiles/files/35920829043.pdfIn PDF document text
    • http://linyuepharm.com/upload/files/bapeziwatorulabiju.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/45891547375.pdfIn PDF document text
    • http://zoscm.zohukum.com/ckfinder/userfiles/files/mukagelaxetuj.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/masoz.pdfIn PDF document text
    • http://tongkhomica.com/upload/files/furaruno.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/kikujuledutiviguke.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/panivabekusalawur.pdfIn PDF document text
    • https://10glazsikeyrosa.ru/file/sevomu.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/jusiwewimujewiguxufivu.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/11305578724.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/41432830129.pdfIn PDF document text
    • https://akanaymatbaa.com/calisma2/files/uploads/fiwejotodigigato.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210905065513.pdfIn PDF document text
    • http://avon-bratislava.com/files/files/fegak.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/1800446793.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_off0000aec4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEC4 14788 bytes
SHA-256: 2002d87c3f26ec072126702515d82929d066157fb2b1f957b7b7fd03f700299e
font_01_sfnt_off0000d3e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ebfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBFB 10852 bytes
SHA-256: 4735a24e1b169bc0c87245d4f3862a0de0c8b9189a0fe8bdc5256fc0379839e9