Malicious PDF — malware analysis report

Static analysis result for SHA-256 53f6ae81f63e9623…

MALICIOUS

PDF

66.2 KB Created: 2021-09-27 03:42:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3ca22f0a3c19ddd7a502e40097491fa3 SHA-1: ed602a74d31b51b8a5ee98712f742a23ffaf3e1b SHA-256: 53f6ae81f63e9623397ab7bdb71994caf2944221b98ca502ad7f4f22090a0771
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as malicious by ClamAV and ML classifiers, exhibiting characteristics of a phishing lure with an image-only design and clickable action triggers. It contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress uploads, suggesting an attempt to distribute malicious content or redirect users to phishing sites. No scripts were extracted, but the PDF structure and URL patterns are indicative of a common phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 66 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://cructi.ru/uplcv?utm_term=tamil+words+starting+with+ko
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/654e389ac7bf19f5d810eca9c00f4044/27010619750.pdf
    • https://sherwoodchamber.org/ckfinder/userfiles/files/46648573963.pdf
    • https://casalindasbakery.com/ckfinder/userfiles/files/raxerijizareleturepud.pdf
    • http://sushikyototogo.com/uploads/files/55125464253.pdf
    • http://hoanhaochemical.com/uploads/files/46043108649.pdf
    • http://cncsprings.com/d/files/45983400129.pdf
    • http://esebtekstil.com/resimler/files/vubibapejifereni.pdf
    • http://nenorm.com/files/files/muwusojukanibot.pdf
    • http://sciattella.net/images/file/53916304247.pdf
    • https://dichvumayphoto.vn/webroot/img/files/4690869081.pdf
    • http://liyangah.com/Upload/file/moxewapotoduxuxomusut.pdf
    • http://tryinvest.eu/userfiles/files/mabamideluwagurirexa.pdf
    • http://mbjarrahi.com/UploadedFiles/New/file/sopiwivemib.pdf
    • http://haraj-alqunfudhah.com/userfiles/file/15311677103.pdf
    • http://refah4ter.info/basefile/hotelrefah4terir/files/papuse.pdf
    • http://liqaa-lb.com/files/userfiles/files/80244384451.pdf
    • http://thesecurityguardunion.ca/userfiles/files/50218388263.pdf
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/23232ca7db21f3996283fc40eca9990d/22819160733.pdf
    • https://wrd13.com/force/file/82691989679.pdf
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/58a5aab56c5c44994dd5576fa3f8acfe/16761706315.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_off0000a951.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xA951 16792 bytes
font_01_sfnt_off0000c168.bin
33dcd2544ad455a2f72479433f0a2eea4c804d02fca4d8295dfd5638eb7c57ab
pdf-font-stream PDF embedded font (sfnt) at offset 0xC168 10704 bytes
font_02_sfnt_off0000d98d.bin
c22c072e5e139fa9408bd073e511a6d921eb5aa670e1d72ec04a74c190dc25d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD98D 13904 bytes