Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a518320630670aa…

MALICIOUS

PDF

80.3 KB Created: 2021-09-13 20:04:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 89ede78c8f24ac46ab59de09a9e32117 SHA-1: 61d8531bcd44ef2e5048eb8c3df39376dad1fb26 SHA-256: 5a518320630670aabf5861738c067be63dabc6cdb77c2ad226ce78fe6bcadb40
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external links, many pointing to potentially compromised WordPress sites, suggests it's designed to trick users into downloading further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further support this, indicating a link farm strategy on disposable or compromised hosting to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 8

  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://wsystem.sk/userfiles/files/77431582405.pdf
    • http://houselandia.ru/files/limogomakibevudexomevo.pdf
    • http://www.siposferenc.hu/html/sozekosupulopuvaloduraxud.pdf
    • http://volvo-cars.jp/js/upload/files/97284862608.pdf
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613138f0156a8---dizuzesudibasulij.pdf
    • http://sancheonglittletheaters.com/upload/userfiles/2021/09/files/210907095620.pdf
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/koresetinozuberix.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/9dd5f0164ccc06b65fb4615299258c45/54667158567.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec533b7588---31651556747.pdf
    • https://chetanaus.org/bheru/uploadfiles/file/61543060968.pdf
    • https://dehayemek.net/upload/ckfinder/files/41960009756.pdf
    • http://bagliodeimille.it/userfiles/files/32090952071.pdf
    • http://toonesk.com/upload/kobelajulebavezelopegesid.pdf
    • http://viettelhaiphong.me/data/dulieu/files/teboruzudoze.pdf
    • http://nhakhoasaigonkimcuong.com/uploads/images/files/gadefegim.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613328140836c---jotorupi.pdf
    • https://cvssteelex.com/ckfinder/userfiles/files/8325340533.pdf
    • http://scoutpate.com/userfiles/file/65123882302.pdf
    • http://predit.ru/admin/ckfinder/userfiles/files/xaxapuxijifeduga.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=viva+video+watermark+removed+apk
    • 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_off0000d231.bin
8589875e5dec23ff49d143480d29933faeffc15dd3d706e60de1d7857ec185bb
pdf-font-stream PDF embedded font (sfnt) at offset 0xD231 10448 bytes
font_01_sfnt_off0000e9ef.bin
454a429cd2709895bbff91fddaadebd1efca67b9fcc9777d6eebebf0e5c6ca13
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9EF 19240 bytes
font_02_sfnt_off00011be7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE7 16792 bytes