Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c37a148a569fe98…

MALICIOUS

PDF

90.6 KB Created: 2021-07-02 03:02:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8d9cada9ca513758a3c97bbe74523149 SHA-1: 0a3a29c2f9c927efa7f1056e5b3daa04334f1365 SHA-256: 8c37a148a569fe987f1356d5ffb8f4f2fc4cb4ea19e5a588c07903b3749e940d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress uploads or are part of link farms on disposable hosting, as indicated by heuristics like PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chelseacarpet.com/ckfinder/userfiles/uploads/vifimejom.pdf
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/94614331173.pdf
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095321f10157---1989077426.pdf
    • https://troypin.com/calisma2/files/uploads/4237226685.pdf
    • https://baoyi-chuck.com/ckfinder/userfiles/files/mezebalisajunibulefifu.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16099bfb17c6c2---5609047052.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/ih8vou9epjtggjjodclikv6sha/62103951767.pdf
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/5g9c9s0sjh1kche7rsf1rotjh0/merigabukoxoxujosuk.pdf
    • http://bannails.com/fckeditor_userfiles/file/vivesev.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/c8adadcac94dbd293ad86f07f91b948c/30622624222.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5fdd4ab7e---18196722710.pdf
    • http://wadirumshootingstars.com/userfiles/file///5509441243.pdf
    • http://acecaalcoy.com/userfiles/file/raxer.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4d55d7f5f---kolosadaxasexosenulu.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/0rufjk8pnhee1gqn8cmcs2702q/diwifumonufuputimukutul.pdf
    • http://jjmcp.jp/userfiles/Image/file/68667937648.pdf
    • http://skolicka.eu/foto/images/file/xefagabiralosatiwuw.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160797bdb81ab6---93358008063.pdf
    • http://aaaexpressac.com/userfiles/file/bufafubozewuzo.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072f6a8ccbf4---sadew.pdf
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/613a5cfb288f0dcf3a8fd99529ed354a/femuwosutiworaxot.pdf
    • https://angkoronetour.com/userfiles/file/44386330115.pdf
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/9db779ba304651baf8eea7e4e0eec83c/detusuxelenurapezuwemevob.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=cannon+chesterfield+manual
    • 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_off0000fe7f.bin
b0f67b75031f169f55e6cf48f09491b5edc9433bf9b097cb2b5355963a99d1d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE7F 17464 bytes
font_01_sfnt_off00012c4d.bin
67bde7d0eae624c153b223ccb5653dab22961bc397299d4a808aafbb919f88e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C4D 10872 bytes
font_02_sfnt_off00014541.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14541 16792 bytes