Malicious PDF — malware analysis report

Static analysis result for SHA-256 b28526c7cbe1f55e…

MALICIOUS

PDF

70.9 KB Created: 2021-07-21 03:42:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 37aebbf1b6edbb3a2116ecb6b1f642cb SHA-1: b61784a416f2907a9404e4927995717c1fbe0b7c SHA-256: b28526c7cbe1f55e3a7d8a6466cf90baecde23629a1e7d5c3727b41498b97c9e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm with numerous URLs, several of which point to compromised WordPress upload directories or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of multiple external URIs and link farm characteristics indicates a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 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://przyklejki.pl/userfiles/90445501964.pdf
    • https://0900107678.com/upload/file/90100719044.pdf
    • http://humboldthighclassof79.com/clients/1/19/19f040aad945c40a0acbd79abd3dc6cb/File/82422025420.pdf
    • http://inercial.es/uploads/files/bekegizokaguna.pdf
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160716aeb3da22---nolawipewunagu.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/3jdhfed3gaslconrt09lcae1lu/raratasazo.pdf
    • http://bawaconstructions.com/editorData/file/42518785302.pdf
    • http://vhshf.de/File/34967546674.pdf
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/9a9f22394b40ce00f3f825b21a86ea8b/84931334351.pdf
    • http://amexeuro.com/an3_Uploads/file/32927311329.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/57987849886.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/00b1b9b76f48daae420bf75def5b7f99/limupovef.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607cceafbfa33---jisigabi.pdf
    • https://nazragame.com/calisma2/files/uploads/sewogofujegizumabazata.pdf
    • https://netron.pt/app/webroot/media/files/27168046251.pdf
    • http://limuzine.md/userfiles/file/90190363417.pdf
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/0623ed0bf66caa363a849527f4d008f2/loxazexopiwipatudofo.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d557cde4383---92897546809.pdf
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/5069ec0cc595c678a882a48585b3cbd4/62700087215.pdf
    • http://www.ipkameralari24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df0a6b26b1d---lojivonotegevupeza.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=this+is+my+desire+chords+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_off0000b55b.bin
83bfd105996bde63b2c71b75d0a12a84a543928226cf270afd37a88392863fb4
pdf-font-stream PDF embedded font (sfnt) at offset 0xB55B 15796 bytes
font_01_sfnt_off0000de7c.bin
451422c4b7a957e98914ec0b67332943e6766b8ea2b2168544eeb45962c7e711
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7C 10552 bytes
font_02_sfnt_off0000f683.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF683 16792 bytes