Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cdedb800b768aaf…

MALICIOUS

PDF

79.5 KB Created: 2021-06-30 03:16:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 72b4f7a89ec5e1dca3b72c66daeded8e SHA-1: 0b5746d94c9c32ee3150cb9eb8159608fac16c92 SHA-256: 4cdedb800b768aaf2b4510a749950dbe7c62615f27f372c35c6cffde31249eae
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites hosting PDF files. The ML classifier strongly indicated maliciousness, and the presence of a link farm suggests an attempt to obscure the final destination or distribute malicious content. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or content-distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9781

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://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607067c68b109---jubimigizeg.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081cdfa54bbc---liturezenaxim.pdf
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/4fc7d991cba40cf867a30491967c5c3f/52339751171.pdf
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/29381383294.pdf
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/fb23a4ed8e886525cea05d7e4cfc7307/27543489577.pdf
    • http://gayaarchi.com/userfiles/file/20210530204154.pdf
    • http://anhuifan.com/upload_fck/file/2021-5-1/20210501225146278518.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e9fb167ed---luxiwovarenufaximin.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/ehhop2t775j8csglp7gkmmunqv/sofukonabufulax.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9bba93e06---30822507776.pdf
    • http://autodilykanka.cz/cmsimple/images/file/61514742783.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/nhgtq274q6ebhsj9dljeat2n73/16863493217.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e42e521e3---22964348481.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607302f743dd3---bimer.pdf
    • http://aps-mes.com/files/file/89201077954.pdf
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/f959fe098623ac2194979902856449e7/jekelebeb.pdf
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/92e691ae4a52517bace83263a759a216/91080485725.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4f1536bd2---26381351246.pdf
    • https://moto-trend.cz/public/files/fck/file/25203928494.pdf
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/fd2ad19f761f8053a1ad93829db7adf0/50128600599.pdf
    • https://szabobuszberles.hu/files/files/85071827496.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081571207a72---15126053054.pdf
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/siboxubexuzu.pdf
    • http://w-f-l.de/user_img/file/78143714281.pdf
    • http://grimastone.ru/files/lojaniledemasubofalorata.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=donald+palmer+looking+at+philosophy+pdf
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/2f79850d40610901dabb309c6ebf0aed/32026626899.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bd35.bin
a79c9caf7d9fe7d7e6557dd08284a48a0650ee9668136fadcfdab94fba17ddb2
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD35 16084 bytes
font_01_sfnt_off0000d269.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD269 16792 bytes
font_02_sfnt_off0000ea7b.bin
824c4565004ebd0e6e63ecd2c25a4fc426cc469c2202c7202c6538ccbe96aef6
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7B 16208 bytes
font_03_sfnt_off00011494.bin
f8d997223dfa89a4bad8a5aa7dcc75e674f501d27254192b8af63af7ca648593
pdf-font-stream PDF embedded font (sfnt) at offset 0x11494 11152 bytes