Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c5f198dd4c31a94…

MALICIOUS

PDF

80.7 KB Created: 2021-07-13 22:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1ac690bc8f3ffec3a8a1c9ca2093796d SHA-1: d2b70b3c5e7facc3ad50e80a1afd66f3b0db8970 SHA-256: 3c5f198dd4c31a94242be6c0d232cfde202f541a4f3c9af27927b2ad64648d29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, detecting it as a phishing trojan. It functions as a link farm, with numerous embedded URLs pointing to compromised websites, including WordPress installations. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the true malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

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 https://synerhu.ru/uplcv?utm_term=find+the+slope+from+a+table+calculator
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/0bfa57c5612b4d80dc63925fde7abe54/vupim.pdf
    • https://topjobsnepal.com/ckfinder/userfiles/files/nodesibevobifudodikisuvi.pdf
    • http://wintec-samu.hu/uploads/files/24018521698.pdf
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/20c1690003ea262606dfe9d59edc9e4e/rimodiwu.pdf
    • http://simmsfamilyreunion.com/clients/9/98/98d47f1658d09d39d77ba56043454c9c/File/38815672600.pdf
    • http://jp-photo.cz/soubory/files/66957422425.pdf
    • http://nfc.soo.jp/file/kinawifagapofonadivuwuzal.pdf
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6b876b0baf---majalirafuvogusolonuxup.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092523280bd4---mupozisavadoxaji.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb0ff43ba29---bofazufavi.pdf
    • http://hnspkjx.com/d/files/jebifovejomeviwilu.pdf
    • http://teplospectr.ru/images/files/sujimedejafesinaxuw.pdf
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/morc3pjdm5o388fu5hr5ueisn6/14712411338.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160aa318597bce---41550140040.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a81c9b5674c---jovekolilajos.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160812d34a7f13---98197970640.pdf
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/ko2fjplbomqq69h9vnoaks3bq2/nopusute.pdf
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/7habavi38o3gkspr4bl9fl8a2n/bunikitobutir.pdf
    • http://drthchowdary.net/userfiles/file/81574512543.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/dab6f0790381748a4ca6eb982835d8d2/nerewepodosobumonovem.pdf
    • http://shosholoza.de/file/43666741297.pdf
    • http://alnoorcity.com/userfiles/file/lanudogobelibel.pdf
    • http://wib24-admin.de/uploads/file/sovagoxona.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16087da0840ac6---35170848990.pdf
    • https://gregor-biffiger.ch/userfiles/file/13156996019.pdf
    • 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_off0000d6c0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C0 16792 bytes
font_01_sfnt_off0000eed7.bin
b71f5e0172c4c5fcdefd6ad7ca48ca2846c455a4c433d5c0e2530e58b66ea6f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xEED7 11104 bytes
font_02_sfnt_off0001083c.bin
6f0d40334dda21c112eaeb5932e8b01853e8b1c0bd3f5f8b0c0ca6d617eaf4b6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1083C 17184 bytes