Malicious PDF — malware analysis report

Static analysis result for SHA-256 5eee9238f8d00c99…

MALICIOUS

PDF

88.9 KB Created: 2021-09-06 17:59:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9ef3e4f79077c956e3fa3e36cf53bf36 SHA-1: 56836bcfba83ad06a39a9d124cb738985d2307aa SHA-256: 5eee9238f8d00c992a62979020c2a206417f0fd47cf061327d38eb9c3413989c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by both a machine learning classifier and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external URIs pointing to various domains, some of which appear to be compromised CMS uploads or hosted on disposable domains. The document body is heavily obfuscated and unreadable, suggesting its primary purpose is to host these links rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 http://kaupa.cz/userfiles/file/21030034746.pdf In PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f92b2b1295c---99804359757.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/2bb3ef4c707d3de758148f9a99fe21b3/27706700034.pdfIn PDF document text
    • http://djpress.pl/Image/files/40647485396.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608068416a5e6---kokuwikokapibefig.pdfIn PDF document text
    • https://ekransamara.ru/files/15363047771.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf749f5c825---loniwokorepeximifen.pdfIn PDF document text
    • https://spheresignal.com/app/webroot/userfiles/files/wuwenipiki.pdfIn PDF document text
    • http://paradisetnl.com/FileData/ckfinder/files/20210814_8D103CEB28ADE0E3.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/anunfki80e6vogr0bjula0ev59/38165706032.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/bilozo.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bdcf2d08926---velobusavexazinokuriwas.pdfIn PDF document text
    • http://xn--h49avwqct32ewe967crscpsaz7d.com/ckupload/files/8044789661.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161173fe9e7674---kojekanozufemizoniga.pdfIn PDF document text
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/40d088e2262a2b171813dd0dab205abe/mokifujidejokabuwo.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080abb7a671b---jixezavoru.pdfIn PDF document text
    • https://jungleflightchiangmai.com/Uploads/files/49724237951.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/c185ce30ab0b9b563cda091dd9ca5c4e/kiwigumitemawusazunujutuz.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b92f4b05a64---mazubowotawozawazowisid.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/90717599433.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/7851635264.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d3963a00914---zipevotisig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=irregular+verbs+-+example+sentences+in+all+tenses+pdfPDF link annotation
    • 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_off0000f4d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D8 11236 bytes
SHA-256: a028b9057141f0f52d6970874a998a683033fcf90bf9faea3cf547678ecea955
font_01_sfnt_off00010ed4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED4 18088 bytes
SHA-256: 4d62ca8eb42ee954e98bb1fb994290af66f26ad4a2be753793d9024269ae0544
font_02_sfnt_off00013d82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D82 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1