Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd73ebba0b784728…

MALICIOUS

PDF

184.7 KB Created: 2021-06-30 00:37:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 511a449234ebbadec59cb29775ee795d SHA-1: fbe0207869710b062046869732979f5b75dfb1ac SHA-256: cd73ebba0b7847288d80ac146688e1f4afbd22e85b49c97adcabe8c3889c7f11
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a link farm or SEO poisoning attack. The presence of these links and the nature of the heuristic firings strongly indicate a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/02b8e2c509aa5e78e7affe83f709a604/98671211194.pdf
    • https://liantoong.com/archive/upload/files/nudef.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608df66b01a14---51052971157.pdf
    • http://hakkabrothers.com/userfiles/file///46863637800.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/csu93usr3t91uoif9sbbcq0l52/96399140590.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609286fb9238d---befinulufokidowobene.pdf
    • http://bjhtdszdh.com/v15/Upload/file/20215221245216646.pdf
    • http://inglewoodreunion.com/clients/68690/File/41351790318.pdf
    • http://1960whs.com/clients/7/73/73384dfd0d582a2861cf356c55c3c578/File/pokanod.pdf
    • http://altelaw.com/uploads/image/file/togexumara.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/4c5edff831179f15c31a5cfba4e37d89/bobomategun.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609bdc751ad8f---96690081904.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c94b8515a4---73284237367.pdf
    • https://armagedonspedycja.pl/files/file/54517386514.pdf
    • http://pajurioverslas.lt/ckfinder/userfiles/files/6106119074.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a94bfff152e---90596710571.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1dbcd3dfc---49665501024.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8f0852d92---pipogol.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090cea8e2721---leziseginufivogejovewe.pdf
    • https://arerp.kr/data/file///48436256228.pdf
    • https://vietfun.com.vn/wp-content/plugins/super-forms/uploads/php/files/p68giss0b6440e89hi0r3l2d6u/74212321907.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=microelectronic+circuits+sedra+smith+6th+edition+solution+pdf+free+download
    • 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_off00026abb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x26ABB 16792 bytes
font_01_sfnt_off000282d2.bin
41aba7877eff56dd4dff2f95a9a4e98bc580edfa43d9e68c15ee92aff3a926d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x282D2 11232 bytes
font_02_sfnt_off00029d07.bin
3060168eefa9db56c2a94af99a8b2159a0c11e0b7a1808bb9bf22eea5b7b4296
pdf-font-stream PDF embedded font (sfnt) at offset 0x29D07 20428 bytes