Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a51d2644e652393…

MALICIOUS

PDF

82.3 KB Created: 2021-08-16 04:22:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c0bf47624067889249b2496b97664ebb SHA-1: 8b5298882c7893c4660a1ada14c0e36f3753d5b7 SHA-256: 6a51d2644e6523936dd743edcf45007d616f9ccc5957057f07fc19feda9761fc
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating it likely exploits a vulnerability or contains malicious content. The presence of numerous external links, including those hosted on compromised CMS upload directories, suggests a phishing or redirection scheme designed to lead users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://sskj.pl/userfiles/file/dubofed.pdf
    • https://publicbridge.pl/userfiles/file/woxadenususugixinunu.pdf
    • http://aep-tc.com/cache/fck_files/file/biwutixorose.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/fmih808n9reo4fhobpuv0il4ci/81331949501.pdf
    • http://mondoacquapiscine.com/userfiles/files/revugegupisuvijuzemapi.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbd8ed57533---84487803479.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160cabedee298b---962107977.pdf
    • http://hglobaltour.com/FileData/ckfinder/files/20210803_5BA8981132EFB85E.pdf
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1610fb615345af---22481385051.pdf
    • http://www.hmcpacking.com/uploads/files/pemusujolaronu.pdf
    • http://modernplating.com/userfiles/file/zefezavapopukolabex.pdf
    • http://ecohouse-lab.de/userfiles/file/vapozofarafiteluvavatije.pdf
    • https://ctners.com/ckfinder/userfiles/files/majivisepuwinogujefelusu.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/48rsmq5j04marc7lqrbhfl3a7c/puzulinimevenu.pdf
    • https://035620126.tw/upload/greenkitchen/files/rofumakeg.pdf
    • https://85097781.com/upload/files/maxuxekopuxepa.pdf
    • http://wsystem.sk/userfiles/files/56934679028.pdf
    • http://champagne-marc-chauvet.com/images/files/60543544577.pdf
    • http://bakerfamreunion.com/clients/1/13/13be4b03bdabdd3a133c3ee64ed6201b/File/72692980655.pdf
    • http://www.almansori-ye.com/almansorifiles/files/95008868343.pdf
    • https://falconshipping-uae.com/userfiles/files/61656751784.pdf
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/11535901513.pdf
    • http://sushimura1.com/uploads/files/59146278867.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160945c901e3c6---nafususasap.pdf
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b26e34b04---fuganomasupilokapiris.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+do+blister+packs+work
    • 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_off0000de40.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE40 16792 bytes
font_01_sfnt_off0000f652.bin
8d4df9d207380eda1c869bd631ac81a89f4c95ca1952ef134736b2a3a98927df
pdf-font-stream PDF embedded font (sfnt) at offset 0xF652 17728 bytes
font_02_sfnt_off0001231e.bin
8fef03f203c3f67b9b718b63eb4d7b90c8c11dfe64a1e6566b09b892e9aa30ff
pdf-font-stream PDF embedded font (sfnt) at offset 0x1231E 10712 bytes