Malicious PDF — malware analysis report

Static analysis result for SHA-256 eab91d90bc3cee7a…

MALICIOUS

PDF

75.2 KB Created: 2021-07-02 07:43:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8f6bd12ae7c77a32b9643cb95bd0fdcc SHA-1: 603c083250b05b471078b1ec9f50c8ef001bc37d SHA-256: eab91d90bc3cee7aea240be4d8152aa2854a8db1ff6e8aa02dbe884c4d7c332b
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to other PDF documents hosted on compromised websites. The ML classifier strongly indicated maliciousness, and the heuristics suggest this is a link farm designed for SEO manipulation or to distribute further malicious content. The presence of multiple compromised CMS upload links reinforces the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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://topplene.com/upload/ckfinder_temp/files/20210612190238.pdf
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b7aadc96e---77754639914.pdf
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/mccshnr8nev89ica4e1snf1jhg/jibavazelunovoxefexexuju.pdf
    • https://coastalstudio.com/images/main/file/60823608381.pdf
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ab6a45725e3---darofa.pdf
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c65904c976---mepuvovinizenimidum.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d932e14d7---95217550719.pdf
    • http://say-international.eu/userfiles/file/forelobefoneraxopuvegulu.pdf
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/81dc9eefe7e3a37ada0596961219948e/pazaguzitofemififenegejal.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160876fe044615---wukexinej.pdf
    • https://xn--nmqu14inmf.com/upload/files/13831677919.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091eb1ebfccb---68798051052.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b746776965f---wokazeji.pdf
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/e7589c6fb962769b660b2e51f63cbbb7/76571718744.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/01d23025b933a9ff1f7aaf3af19d5155/jajeroxomeromejewof.pdf
    • http://abw10thstreetne.com/uploads/files/saxivufopimurovewesavaru.pdf
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/1v8ockm6gg0idje7lsuardn62c/libipowizawakokin.pdf
    • http://poltinka.ru/userfiles/file/20053696656.pdf
    • https://colakcivi.com/userfiles/file/sixipukotuxamuxe.pdf
    • http://3bbb.fr/ckeditor/upload/files/25752390294.pdf
    • https://ptogel2.com/contents//files/womimupekoziro.pdf
    • http://matthewsmillsreunion.com/clients/c/c7/c7863f7b93cb17915b2a89d887155530/File/fogogobazitodikifato.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=coc+base+town+hall+5
    • 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_off0000c592.bin
0a3b9df370154a0e5a857198ebdad98d16a53f4a35594739eae5e2e461e47723
pdf-font-stream PDF embedded font (sfnt) at offset 0xC592 10524 bytes
font_01_sfnt_off0000dda9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA9 16792 bytes
font_02_sfnt_off0000f5bb.bin
bcf18c92128b363d1bb50cc67179fc6f1524d39f157d67e7e181c06bdf8caebd
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BB 16656 bytes