Malicious PDF — malware analysis report

Static analysis result for SHA-256 e50c492cf997d75c…

MALICIOUS

PDF

91.0 KB Created: 2021-07-03 20:07:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 73818f0f06df88222ad7198b2e882b9d SHA-1: b56b114de9f6fa3b69ef0a59f26bcfb306b5daaa SHA-256: e50c492cf997d75c6078f202ec7431f0278b33d1c8ef9a0590c969f6ef56bab9
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files hosted on compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body was unreadable, but the URL structure and heuristic firings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • 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://straps.by/ckfinder/userfiles/files/19927214850.pdf
    • https://petek.biz/resimler/files/85325453887.pdf
    • http://utopiasacramento.org/clients/0/07/071cdeedc048305be324eb10ab8031d4/File/zirekamizafuzulosaf.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/129772920e934c4e340e5f4a10b5f508/72392415538.pdf
    • http://joy05.com/_UploadFile/Images/file/17200589261.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba4c6c76544---jikixunofuwosa.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607213b1585aa---rojiwa.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16098a27b6b3e9---ruwexebamebofesonawej.pdf
    • http://pcccphucvinh.com/upload/files/79754252308.pdf
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9f2395583---xidoxaged.pdf
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1607a80351239f---kegujusafe.pdf
    • https://cplastik.cz/data/cms/file/34069576359.pdf
    • http://haniltm.kr/upfiles/editor/files/78302742939.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4a3dea3a9---lilupiponurojuzavulu.pdf
    • http://guides2alpes.fr/uploads/file/joduwuzalasuvoza.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6018e3a52---36768946258.pdf
    • http://yngc.ru/admin/ckfinder/userfiles/files/29476346000.pdf
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/b799037ddced05734f7bcc6b032bd1f7/29478215432.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/c76e71f80c0ef1440827a1715b363f49/fufurimenakiwa.pdf
    • http://askort.pl/Upload/file/45974968477.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/f89bf00449b0a2a6ab982972d9d46ea7/25420892380.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=whole+numbers+are+closed+under+dash+and+dash
    • 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_off0000e9a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A1 16792 bytes
font_01_sfnt_off000101b8.bin
94258a85776cb761cba2bba4cc98327f6fd46b9e0b323a7fa54cba4f1b0bf8b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x101B8 10680 bytes
font_02_sfnt_off00011a06.bin
b5512483b7241b8879d704941c68e68fc66f7378ac9744f9a61b738fa4f49b0d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A06 18036 bytes
font_03_sfnt_off0001493f.bin
450eea5fc67953cc3bdc764260aa6f1739571c17331c9588074966c3dbef4c6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1493F 16088 bytes