Malicious PDF — malware analysis report

Static analysis result for SHA-256 633ef8a533662e9a…

MALICIOUS

PDF

83.2 KB Created: 2021-09-04 09:50:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: db8e36a7c51fad40f8f85a63c8185100 SHA-1: 6e25f46145fa6803dbf4b37faecb002964039cf1 SHA-256: 633ef8a533662e9a20d9bfcf261982ea9dd18a84e6c66aa0ad1de422ef60f184
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous URLs, including those on disposable hosting, suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • 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.
  • 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://thinhhoanggia.vn/Images_upload/files/vuzuvakuzi.pdf In PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3c6b889dc---47231976473.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/jifexajovasatewuku.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1612be9e61df95---vibogezunedosevomev.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/32119276652.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/tujufasa.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/wupujafe.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/tibumed.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/5335683986.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/579bf44ca41d12fa296ad55921cd1c01/69691582258.pdfIn PDF document text
    • http://thedreams.cz/files/85188172614.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/p5rmb443vjaprsav7ckkn57mh1/dutitikutobupametile.pdfIn PDF document text
    • https://newsru.md/upload/userfiles/files/34501402827.pdfIn PDF document text
    • https://kolbandibileklik.com/resimler/files/metaxodefideresunakeb.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/15a3fec5bc0aaf0f7bdb2d025aa9bc88/3242684418.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fa9251871cc---digod.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/bejurojonugexago.pdfIn PDF document text
    • https://webmenuplus.com/images/file/25591113013.pdfIn PDF document text
    • http://chapelguild.com/images/usr/48558253974.pdfIn PDF document text
    • http://ssteelelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/90158709970.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2467e849e---3384631062.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=writing+numbers+practice+pdfPDF 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_off0000e0d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D0 17540 bytes
SHA-256: a5a8d0b32cce814d9ad4f807f0ac86942a55a10a962e57e17f27bb11c71d9f4a
font_01_sfnt_off00010d8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125A3 11032 bytes
SHA-256: 0c243f0330e8807dd05ef8bd008773c0c16f8184a7f068fed1b95c3b76f5d4f0