Malicious PDF — malware analysis report

Static analysis result for SHA-256 53c3ea004ca0e6df…

MALICIOUS

PDF

71.8 KB Created: 2021-10-02 18:19:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 252bb34876684850f9ef2205d1e69d2a SHA-1: 768a8710b160181fd35905ac2ab91d636fba16c7 SHA-256: 53c3ea004ca0e6df6a8f9b561b94c0955bb4c06a517cef5e33ee14b88fc6376d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is a primary mechanism for executing malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://drafthe.ru/uplcv?utm_term=general+knowledge+answers
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/korimer.pdf
    • http://laser-piskovani.cz/democms/userfiles/file/wezekarebasixetumonurox.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/9522e2c0eeae3ce30a5d9a3127533a63/12898182702.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/c8b6425db08781f83eb9d79eba9eaf04/61425012938.pdf
    • http://hacoauto.vn/upload/files/70515147720.pdf
    • http://carlaschroyen.com/content_docs/95229975805.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/61589183425.pdf
    • https://avenue102.com/uploads/file/60911950888.pdf
    • http://terralis.eu/catalogue_dynamique/file/87612692767.pdf
    • http://emrc.ie/upload/imagecontent/file/xefufatedibekotijosa.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/75326608653.pdf
    • https://stw-nowogard.pl/download/file/57610514690.pdf
    • http://veterky.ru/ckfinder/userfiles/files/60595988548.pdf
    • http://w-f-l.de/user_img/file/33493421994.pdf
    • https://onthespothousing.com/userfiles/file/43959647497.pdf
    • http://konditsionery-reutov.ru/upload_picture/file/tunaduwoze.pdf
    • https://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/50700866593.pdf
    • http://paroissedementon.fr/upload/files/7885750689.pdf
    • http://dulichtantai.com/files/uploaded/files/jojupozokipumi.pdf
    • http://scandinavia-ex.com/images/blog/file/5631657712.pdf
    • http://ballarioarchitetti.eu/userfiles/files/negilifa.pdf
    • https://twinslock.com/ckfinder/userfiles/files/kugazefepidinadoxul.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614faa416385d---50809170871.pdf
    • http://studioarclab.eu/userfiles/files/97413716571.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_off0000b3f9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3F9 16792 bytes
font_01_sfnt_off0000cc0b.bin
d0849230879b41d1d917a48b7aeda4802a863da8e6ea01491592d1d2d6a03eae
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC0B 18348 bytes
font_02_sfnt_off0000f9bf.bin
1ef7aae3dcb307bcb0706e092c76e652957c4d175e6d00f303fda8af141f9027
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9BF 10452 bytes