Malicious PDF — malware analysis report

Static analysis result for SHA-256 85418f81b614243e…

MALICIOUS

PDF

68.2 KB Created: 2021-09-18 08:24:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a19c6454751531a026347d8378e04387 SHA-1: b3a4805963401c4e49e195181349232ccfbc8f26 SHA-256: 85418f81b614243e73e1d230943e71c6901a0b29bcb34bbadf6ced28915fa7d8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of creating numerous small PDFs on distinct hosts, suggesting an attempt to manipulate search engine results or distribute malicious links. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://coretry.ru/uplcv?utm_term=snaptube+old+version+app+download PDF link annotation
    • http://friend5190.xyz/js/ckfinder/userfiles/files/vekal.pdfIn PDF document text
    • http://cpghollywood.com/userfiles/files/45695087034.pdfIn PDF document text
    • http://pinzimoniofiumicino.eu/userfiles/files/96576588977.pdfIn PDF document text
    • http://ozanatalan.com/iboard/includes/userfiles/files/wevazir.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db97501865---73951217579.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/kugenazala.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/zoxujudobabeputob.pdfIn PDF document text
    • http://avrig35.ro/uploads/fck_editor/file/mewafexosumu.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132588b071a8---kafadirujutupuleb.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/13478433966.pdfIn PDF document text
    • http://thamcohoaian.com/webroot/img/files/33500759596.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-9/20210909235022540741.pdfIn PDF document text
    • https://groupburuemas1.com/contents/files/butisa.pdfIn PDF document text
    • http://vititanon.com/user_img/files/16357484276.pdfIn PDF document text
    • http://tccsrl.org/userfiles/files/koniviriro.pdfIn PDF document text
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/lajozofukoxilogur.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/f3c1tpev98oekioi9cuvl91gh7/fibiwijebazipizufaserataz.pdfIn PDF document text
    • https://marmetal.cevhertemizlik.com/userfiles/files/silurokuxanixemaxeme.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/zesekatomo.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/jawewejafireni.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/lipatisuvo.pdfIn PDF document text
    • https://presstone.hu/userfiles/file/wovot.pdfIn PDF document text
    • https://lesrimaudieres.com/images/uploads/file/65190127084.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_off0000ae19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE19 14436 bytes
SHA-256: 8c9f84128a6a870d9182ee6d6a6dadd5480c1db0b652366b469bd7f5662efdd9
font_01_sfnt_off0000d255.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD255 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6C 10852 bytes
SHA-256: 34ab864cdda19687c572c0e2fb61e70eb1fbb75feb858270db9c5560fa0cf850