Malicious PDF — malware analysis report

Static analysis result for SHA-256 15f4c517da8f876c…

MALICIOUS

PDF

70.6 KB Created: 2021-09-25 02:13:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 851dd36108be95b431c7243f4befd743 SHA-1: 85690ab737ad4fc63f95a34832a4ac6cafe53826 SHA-256: 15f4c517da8f876c98f734581c9e3bd032d75cdfb87ad10903565850d03d1533
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with SEO poisoning or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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
  • 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.
  • 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://pistant.ru/uplcv?utm_term=how+to+transfer+contact+from+android+phone+to+iphone
    • http://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/51243492856.pdf
    • http://miwon.vn/app/webroot/uploads/files/dujudotokonuvatoge.pdf
    • http://scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/36778237245.pdf
    • https://vieclamlaocai.vn/webroot/img/files/pobisabikizovixef.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614984c098459---64387853848.pdf
    • https://bunian-co.com/other_files/File/zeriseg.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/35bbc9e5af2361069aa181f32b78431e/46729386826.pdf
    • http://diakmelo.hu/ckfinder/userfiles/files/39961288437.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613a858070cf7---vuvozos.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148701013426---67662680636.pdf
    • http://rickgrisolia.com/userfiles/files/21900584953.pdf
    • http://bike-aholic.com/UserFiles/file/zajebuvor.pdf
    • http://edeins.com/userfiles/file/gabulipagabosav.pdf
    • https://deepex.hu/hirek/files/vumazefuxovanan.pdf
    • https://dichocungtoi.com/userfiles/file/26821684697.pdf
    • http://buffagiuseppeinfissi.com/userfiles/files/mokoxipijigivizefewik.pdf
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/396419695.pdf
    • http://studioguagnoni.it/userfiles/files/79554288899.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d4d88edb5c---79118442416.pdf
    • http://www.northern-japan.com/image/upload/File/20691377211.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614acc1be33b0---waviwarejodifatutufu.pdf
    • http://merrygoldholidays.com/ckfinder/userfiles/files/bikedugeje.pdf
    • http://sklenicky-obchod.cz/web/admin/fckeditor/userfiles/file/wafunavawunaxuninezirip.pdf
    • http://utcsp2.rustyramone.com/uploads/files/semimemadomirakavefukuv.pdf
    • http://gamax-motor.cz/data/dokumenty/36277553719.pdf
    • http://hatdesechia.com/storage/ckfinder/files/mipuvosevasujixezo.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b386.bin
fbf043773a25827123b32cab4960ac7036fb025cc141a65a08b9f3330bb280c1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB386 15592 bytes
font_01_sfnt_off0000db56.bin
375fcd1656a7e077188ad3f69b253632a8140f992417f91619457da0c840e009
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB56 10916 bytes
font_02_sfnt_off0000f475.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF475 16792 bytes