Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e7541861c08ef9c…

MALICIOUS

PDF

74.0 KB Created: 2021-06-25 15:07:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e33aeee2cb98bf04eb265f4c0b7f8b4a SHA-1: a4f61effe5270c9fa27992e912db0596b71df817 SHA-256: 4e7541861c08ef9c1f6efc01dbfc4cacfbbce395604492442d6f13b741ed4505
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple URLs hosted on compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and does not provide direct clues to the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16071cbcd1f7b3---subixilu.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/9fede863c06292b4909d79f3e38af700/varideriv.pdf
    • https://ringid.vn/ckfinder/userfiles/files/79244792467.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1606f595cc790a---1191394472.pdf
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5b4fb0b38e---pugebek.pdf
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1608714009d45f---27978913839.pdf
    • http://lubrifianti-auto.ro/files/file/92932025348.pdf
    • http://cdwy028.com/uploadfile/file/20210615154550.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b035647b9a---dimumupopiva.pdf
    • https://mides.vn/images/ckeditor/files/nosukat.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608332384c051---xagajizi.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e622f3ce3---kuzipekewazaxebuxa.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/5ootibo1jfg2652v5vdlvhlhtg/29462075958.pdf
    • http://agataklimowska.pl/userfiles/file/jafudibutanidekeku.pdf
    • https://bandotrading.com/uploads/file/31930949591.pdf
    • http://kalkulacka-hypo.cz/userfiles/files/15367126899.pdf
    • https://bmw-zona.ru/uploads/file/xenujizanumagafeze.pdf
    • http://ghalemdi.com/userfiles/file/dodunofuxoxev.pdf
    • https://accuratesearch.com/userfiles/file/lamudibigatimo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=angles+are+complementary
    • 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_off0000bee0.bin
371daaeb84e0fb6762f9ffaa812e66a4d2338524ab41b9755e1ce80def23d78a
pdf-font-stream PDF embedded font (sfnt) at offset 0xBEE0 16804 bytes
font_01_sfnt_off0000eaa7.bin
1b82500e7c3a571035a2eeaaa481fe4e1657344c752754acb97c3fc435b55334
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA7 10720 bytes
font_02_sfnt_off0001036a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1036A 16792 bytes