Malicious PDF — malware analysis report

Static analysis result for SHA-256 277921ad31269fd8…

MALICIOUS

PDF

71.8 KB Created: 2021-09-20 14:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4fe807e1c893efa6db4b6b772925a093 SHA-1: 3e4038b4e7b217c42b6a1975246a7a3e24ce5a3e SHA-256: 277921ad31269fd8c4a59cf640bb21caf186bd1a93ea4280f3a7ec3aa2ca48eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ketchas.ru/uplcv?utm_term=minecraft+download+full+version+android PDF link annotation
    • http://autosoftware.company/autoresponders_images/files/15573619535.pdfIn PDF document text
    • https://xn--23-6kci4asohe8k.xn--p1ai/userfiles/file/50784531641.pdfIn PDF document text
    • http://www.andreapondika.cz/file/pududowibuwolaraf.pdfIn PDF document text
    • http://urbanelect.com/userfiles/file/zoxuzefodofebizewa.pdfIn PDF document text
    • https://ta-taiwan.com/app/webroot/userfiles/files/51118878445.pdfIn PDF document text
    • https://viscom.bg/uploads/wysiwyg/files/vimegusofadizipiguge.pdfIn PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/gaxugaxebasiwifopoz.pdfIn PDF document text
    • http://baruraprotidin.com/assets/ckfinder/core/connector/php/uploads/files/juluwowaduwegotov.pdfIn PDF document text
    • https://eric-parnes.shortex.com/ckfinder/userfiles/files/nosezodaxa.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/vexebebosur.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210901123131.pdfIn PDF document text
    • http://mydreamtuscanwedding.com/editor_up/59203025042.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210916223425.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/dolorajeruwawi.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/bixawakif.pdfIn PDF document text
    • https://cmoretv.com/userfiles/neporojuximepav.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/bakorudo.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/sogituzo.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/161323df49584a---30579008497.pdfIn PDF document text
    • https://rt-totaalafbouw.nl/userfiles/file/31529633901.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/vol77q644dnsktfos9lamegim1/52273579078.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/malar.pdfIn PDF document text
    • http://dubilex.com/userfiles/files/43250710825.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109192350379912.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB690 16340 bytes
SHA-256: 58422c1f7ec11d6fd9fa8ae9a245e93b3800dc45c27861d804c55596f4689b8f
font_01_sfnt_off0000e040.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE040 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF857 10716 bytes
SHA-256: 2385e7fb1bfa35f446395f5e86c6a8f6770f669a16b45fb60f0b1dc3f16f104e