Malicious PDF — malware analysis report

Static analysis result for SHA-256 171dc7c41cae2108…

MALICIOUS

PDF

80.3 KB Created: 2021-06-14 13:58:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: c26c141985422af609ed60892c77c112 SHA-1: 9309d36a18ea62e27b52a6c72a19d83b5b4e2f9a SHA-256: 171dc7c41cae21088301bd644555a5de679b02945cc668b3d96e8a44d32ac68d
164 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains text related to downloading English answers, a common lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://irlanc.ru/uplcv?utm_term=class+10+english+answers+pdf+download PDF link annotation
    • https://abeess.com/userfiles/file/tojajovone.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/25297843962.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/1f5f77ddbc118c2134cbd263ca4ace19/gujuvodubuvoxifakudeb.pdfIn PDF document text
    • http://vce34.ru/attachments/file/korakepaxazedifomu.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/92fdf60d29792e45efacda3d187f0875/naradoputilifejovenuwub.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bf8a995ea66f1b2a1053318dc0134dc9/36938632805.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/51097374373.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0334d6f45---37180398861.pdfIn PDF document text
    • http://zeguvietnam.com/uploads/ckfinder/files/kepefiwunum.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/rkomqirek13hgh114qlb39c1fu/46056320676.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/1paqp2n6nv509qp8827t1o85uk/xutudidivuraziguwasetib.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/46394035188.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/letjgh8mas16cv2k78i8nukf5d/19332840141.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/ef9d197d48f5903376a57a4255e4bf44/53324006218.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16081760073590---47717187501.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DC 5320 bytes
SHA-256: a3896725f4a49a6596a8f474536ee01c406a06da7778f7aba37ab8ac19fec8ae
font_01_sfnt_off000104f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F5 10484 bytes
SHA-256: c6c35ae04ea599c319566059dab76c9ca0319af3d8f119d3c358cc81bdaf61e2
font_02_sfnt_off000128b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128B6 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34