Malicious PDF — malware analysis report

Static analysis result for SHA-256 775bab9da127e8bc…

MALICIOUS

PDF

78.9 KB Created: 2021-09-17 11:16:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bffc20a5a3faf28856c79f29a82e8b47 SHA-1: ffe082c56ba1084b4f0f5a4544791cd4dc57025b SHA-256: 775bab9da127e8bc1f8681c76bb6e4e899508bba4386698d5c931b74eb65b95a
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 http://roberlo.cz/www/files/file/fotiletovawup.pdf
    • http://fuhua.tumujike.com/assets/upload/files/202109121625139299.pdf
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16135c03abeddb---23246985323.pdf
    • https://comfort8889.com/upload/files/31182671275.pdf
    • http://fratellibeninca.com/images/file/30987848678.pdf
    • http://madmojo.com/fckupload/file/89117379228.pdf
    • https://priscar.com/documents/files/54657237207.pdf
    • https://albertoangel.sinecsas.com/ckfinder/userfiles/files/malipusajikovubekovetabav.pdf
    • http://chpcentre.com/files/file/17681968286.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16142543fc6b3a---wazajotosuxefovozi.pdf
    • http://hstairan.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/sarubuxelavisof.pdf
    • http://atenngo.com/admin/sites/site/documents/17646803606.pdf
    • http://kisito.com/userfiles/file/2941195447.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/31699504844.pdf
    • http://idominjazz.com/fckeditor/userfiles/image/kopanefulos.pdf
    • http://batiment-tunisie.com/userfiles/file/27142350602.pdf
    • http://ahchala.com/img/file/tunefitokativaxem.pdf
    • http://ingegneriarossi.it/userfiles/files/vudajosisolikisag.pdf
    • https://pagodatalk.com/_UploadFile/Images/file/21192111441.pdf
    • http://freeware-software-download.de/uploads/editor/file/fakanuz.pdf
    • https://hanoihome.net/img_duhoc/files/kiruf.pdf
    • https://study-abroad-travel.com/ckfinder/userfiles/file/90564692244.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ddcd41d7c4---46395863394.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=the+walking+dead+season+10+episode+21+watch+online
    • 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_off0000cf0e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF0E 16792 bytes
font_01_sfnt_off0000e725.bin
f7caaa197e2e044cf857fb6ccff602c8aa417d7d5eeb19fa6b8d4e8f507de2fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE725 11128 bytes
font_02_sfnt_off000100fc.bin
ea5cbdefc31c1d8d9b058d2326ab08343a943a87ad758a115c7f3c43149b98c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x100FC 17104 bytes