Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0f1efbed8c56301…

MALICIOUS

PDF

86.7 KB Created: 2021-09-15 12:33:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ed61c75d895473387d6b8ed57ec0345 SHA-1: 4b5e3e9ecb7b4ac6dcc427dc63384db980446642 SHA-256: c0f1efbed8c5630178d2333bd9e2fa51a38baec160f06450b88befd689fc4242
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 upload directories. This suggests the document is designed to act as a lure, potentially redirecting users to malicious sites or prompting downloads of further malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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://irlanc.ru/uplcv?utm_term=best+build+up+games+for+android
    • https://autotronics.vn/userfiles/file/41151706410.pdf
    • http://ydchem.cn/filespath/files/20210913004859.pdf
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/b64559034e7b3dd0b1661d81b3142623/lubalule.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16137399f431d0---kiwomit.pdf
    • http://predit.ru/admin/ckfinder/userfiles/files/rolaziropisexitomovi.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396f0c4df23---wibuxusujonulibo.pdf
    • https://natinsel.com/imagenes/file/lavimapetajop.pdf
    • https://youxsoft.com/uploads/files/rigosawo.pdf
    • https://thietbigas.net/media/files/tebuput.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/161390a6699613---nutonagu.pdf
    • http://zdrowejaja.com/Upload/file/61262898821.pdf
    • http://tangiahoang.com/skinkorea/Images_upload/files/pixuteveziz.pdf
    • http://ysmenmidwestindia.org/uploads/userfiles/file/file/dagolex.pdf
    • https://navoloki.mebel18.com/uploads/files/55501653494.pdf
    • http://oldmotorsclub.com/files/file/68502729165.pdf
    • http://sententtech.com/file_media/file_image/file/98883042404.pdf
    • http://pascalparrot.com/uploads/assets/file/pakinebugodogutor.pdf
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/98516919702.pdf
    • https://penzion-pod-rozhlednou.cz/img/file/mutukizusinobutaji.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd6fd93ced---denubadizewumefibet.pdf
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/d17vr7j9grmp1javq69refit0r/24250931376.pdf
    • https://iskoruma.com/upload/ckfinder/files/xigufuzipen.pdf
    • http://halmar.info/userfiles/file/17824825396.pdf
    • https://keiba-like.biz/js/ckfinder/userfiles/files/1141997582.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_off0000f10d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF10D 16792 bytes
font_01_sfnt_off00010924.bin
10a39be6592aa0441c9679a829834e00c3f523fc9ff12ddffde9ce233ee4665e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10924 11132 bytes
font_02_sfnt_off000122ad.bin
e9c5a32cd10861daa6a70a0f91e747ce5dc37dd00ac51cedb1d12ab805b91537
pdf-font-stream PDF embedded font (sfnt) at offset 0x122AD 16656 bytes