Malicious PDF — malware analysis report

Static analysis result for SHA-256 3875daee0edf052c…

MALICIOUS

PDF

73.0 KB Created: 2021-10-07 19:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8a45c928e92fbb15e9aea670aa4bbbe6 SHA-1: a592294313433eb8b831fb87917179161a25cd94 SHA-256: 3875daee0edf052c36e2a86335994215f7a444d92f1c55c32a64eee02e6c420d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier flagged it with high confidence. Numerous heuristics indicate the PDF is a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The primary purpose appears to be directing users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://synerhu.ru/uplcv?utm_term=short+stories+for+beginners+in+english+pdf PDF link annotation
    • https://inprovitparaguay.com/ckfinder/userfiles/files/robokilevefujem.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/dopim.pdfIn PDF document text
    • https://portoggitter.no/content/files/userfiles/file///40849532422.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/80059935560.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/68949553542.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/nobavilefavenenen.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/tabubejuxawipusapi.pdfIn PDF document text
    • https://didacostruzioni.it/userfiles/file/jokozavukawisite.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/mebimapalazas.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/161536be91436e---pidukujivu.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/wusuxelosipusukokimafawi.pdfIn PDF document text
    • https://kolbandibileklik.com/resimler/files/53669682467.pdfIn PDF document text
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/76792346232.pdfIn PDF document text
    • http://mannaz.pl/userfiles1/file/4112240132.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614654a93db6a---luxuz.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/52780106344.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/5522671037.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/20998655876.pdfIn PDF document text
    • https://wickedcheesy.com/images/file/gerekelowarijimalopifom.pdfIn PDF document text
    • https://rivieresoceanie.com/userfiles/file/12082028862.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1615a8bdea0f0a---15179592637.pdfIn PDF document text
    • http://akcompany.vn/uploads/userfiles/file/80146792537.pdfIn PDF document text
    • https://saglamahsapkutu.com/img/editor/image/file/89088266737.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_off0000b966.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB966 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d178.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD178 17300 bytes
SHA-256: ef812ddab50f7469211c666f5c9b456b96d3ae7c23a0e8253a94f954f45760eb
font_02_sfnt_off0000fd9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD9B 10828 bytes
SHA-256: 8ee175b61d5c8bde6e84de932fdee88e84617d45405f7aabbd12b66d68042951