Malicious PDF — malware analysis report

Static analysis result for SHA-256 c35aca957b79404f…

MALICIOUS

PDF

70.6 KB Created: 2021-09-17 19:13:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3ef2c37acb2f466ab4cfee6402f504ff SHA-1: a710a08f0ca992b2a840e6f9d7103b7aa20bda0e SHA-256: c35aca957b79404f3280a37e2fa35750f75b9f8587ebebc3b9fc76470daa8b35
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm, with numerous URLs pointing to various domains, many of which are hosted on compromised CMS uploads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the link farm and the detection results suggest it's designed to lure users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137f3a6b3bbc---59630365508.pdf In PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613c36551a7f4---nuwevawo.pdfIn PDF document text
    • http://avtokit116.ru/!upload/files/renirebaluw.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109101554503840.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/27084412958.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109160951302534.pdfIn PDF document text
    • http://chinatriage.com/ckfinder/userfiles/files/pasabexuwoxasefugaluni.pdfIn PDF document text
    • http://izhar-energy.com/userfiles/file/powepogiz.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/cfc830e231426b0daf72e2e0382c4072/jovopapesavafeler.pdfIn PDF document text
    • http://abwcrainhwy.com/uploads/files/70230019288.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/25144410517.pdfIn PDF document text
    • http://uchid.com/uploads/file/rebotutapunanud.pdfIn PDF document text
    • https://ajansnigde.com/resimler/files/xivedo.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/busemi.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/dedobiwotisivunumela.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/vubeluxusebi.pdfIn PDF document text
    • http://techmechengineers.com/uploads/guruligujifovuvufemuzape.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/82675939908.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0bf9dbee0---kanidanekozanapop.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/42829753266.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/vufoxejejenejuku.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f97c0902ca---gasavugipiguxod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=pes+2019+psp+iso+english+download+highly+compressedPDF 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_off0000b0c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8D8 16024 bytes
SHA-256: 546260bbd6ee8f8da10194290da2164906f1458f4c9e1fb4ce5c759bdfce9bbb
font_02_sfnt_off0000f21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21E 11524 bytes
SHA-256: c3c6371cc9041dda427fa8b16c8cb49c0891867d04d0eea18bb5f1799d941422