Malicious PDF — malware analysis report

Static analysis result for SHA-256 d259ed1c4c47804a…

MALICIOUS

PDF

70.8 KB Created: 2021-06-25 12:04:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 35a52eafe4c8e8611dd95b20136870f5 SHA-1: 288d7dc62cf356fc8f1a6f4d3938782fcb35e557 SHA-256: d259ed1c4c47804a34cc0316ca93348cbd8150427ea19c71853d244ee5fb119c
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories and other disposable hosting sites. The presence of external URIs and link farms suggests the PDF is used to redirect users to potentially malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 https://medvor.ru/uplcv?utm_term=jav+lesbian+movie
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/nl36uae4c4il9ap7ti02hg352u/49278562167.pdf
    • http://www.mostex.sk/files/articles/file/55616748505.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/84e197f9be84a9d03f0e31d8f07a2928/sivonuwitazewirunoloku.pdf
    • https://adepotcustom.com/UploadFiles/file/20210430182753187.pdf
    • https://askisan.com/upload/ckfinder/files/xewuzumekabusuxapufotag.pdf
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/4e606e7274bc87583382188a5c4128f8/funorugat.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/bb69295ec5de1c093e3bf2f227741e30/15971898249.pdf
    • https://cakenepal.com/userfiles/file/70106437976.pdf
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/342bb1f9b882c745f7b362da1e9136dd/82193434377.pdf
    • http://alpha-th.com/userfiles/file/filukegusepusisanuzisu.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/prdc2cgponsdis4hp990n5gvh2/pulid.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608035ad212b9---33976548960.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608164d1bb94d---79845751004.pdf
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/17da6c73f3dd1e07ff08735911ca2371/28585457903.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc055b3770---libuvivafob.pdf
    • https://genesislighting.net/wp-content/plugins/super-forms/uploads/php/files/2769474819aa6f9915a6ce6d7f5e494f/jotila.pdf
    • http://smartvoicecom.com/userfiles/kigozubejodatopivos.pdf
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/a0a0ef78fed49d992fa8d5336cf1a526/96415042677.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_off0000b5a5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5A5 16792 bytes
font_01_sfnt_off0000cdbc.bin
070a825edcc5243b47ff8e08c411c252a8eb472cbe7b70a15abaa779d93e104d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDBC 10268 bytes
font_02_sfnt_off0000e4c8.bin
dee227aab2594bc36fafe8a934562eea665a6873b2f9ffbe9d99dc3c903fb937
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C8 16308 bytes