Malicious PDF — malware analysis report

Static analysis result for SHA-256 f237b7efe7c1d65b…

MALICIOUS

PDF

70.6 KB Created: 2021-09-04 13:49:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d06c736d81cbe2c0193ce12b4407a402 SHA-1: 41322f4609190ad494bc76a6d940a60c1e9997d5 SHA-256: f237b7efe7c1d65b07fb9966fe1f5c3545ae22afad1cde81e317b2c4a86f400e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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://djarkitek.com/temp/vinney/HTML/userfiles/file/norexul.pdf In PDF document text
    • http://mfcpavpos.ru/file/67887244575.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles//file/dejoxeximurekuvapujelu.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/runumotipabose.pdfIn PDF document text
    • http://skisun.it/userfiles/files/kumikumufidorixemedimope.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/d3c209a8eb362fdac5d90ffa050be38b/69400562297.pdfIn PDF document text
    • http://chinalanpa.com/images/upload/File/79358348979.pdfIn PDF document text
    • http://pfmconsulting.org/survey/userfiles/files/mobize.pdfIn PDF document text
    • http://wittzumstegfamilyreunion.com/clients/e/e5/e56c03c63d8c9260b12fda9e5e6a3df6/File/51671373391.pdfIn PDF document text
    • http://thepnguyentran.com/media/ftp/file/22017656058.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/4709080098.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607e43d30bb57---59903127376.pdfIn PDF document text
    • http://mesterek.net/tmp/98754799073.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/lanamuximitenuri.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/gixemaz.pdfIn PDF document text
    • https://vansuloi.com/uploads/userfiles/file/58047319122.pdfIn PDF document text
    • http://sancheonglittletheaters.com/upload/userfiles/2021/07/files/210708122526.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/51459762601.pdfIn PDF document text
    • http://xn--tnqz8hz5cb8l.com/upload/files/renagazaduveniwapatinu.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/83a0e9caa7e231870fffc8e64dae3b72/26549194714.pdfIn PDF document text
    • https://promise-land.com/upload/file/banifito.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/juwovajogigutezazavajetid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=ap+physics+forces+test+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_off0000b2bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAD1 16404 bytes
SHA-256: b61a101b72c874325b30804a87ee1ea3efa035226870e8094e59c23449b894c5
font_02_sfnt_off0000f560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF560 10500 bytes
SHA-256: fd8aa9adf611b8c2add8b367f4469cf98198b04fe97b47acfbb90983559437a7