Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef743916cb8bba50…

MALICIOUS

PDF

77.0 KB Created: 2021-09-12 12:54:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0a23440db41fbea67996924db0e843b4 SHA-1: db8e786a6dad97694db4beeba517f6e5a6d9da9d SHA-256: ef743916cb8bba50037f3efce2b803fe888c0b1c236534575a453c80af41ba91
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The presence of numerous embedded URLs, many pointing to disposable domains and employing UTM parameters, strongly suggests a phishing or malware distribution campaign. The ML classifier also indicated a high probability of maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=super+smash+bros+gamecube+iso PDF link annotation
    • http://srmtteaparty.com/uploads/files/202109020915569274.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/wukasas.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210901211321.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/161372c1f4adff---gonuwar.pdfIn PDF document text
    • http://eskuvoiiranytu.hu/blog/file/59571724384.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/mesox.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137035551a2b---fotivejosugu.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/vigewopare.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/ripaxakifamamu.pdfIn PDF document text
    • http://youngshiny.com/userfiles/file/1631008337.pdfIn PDF document text
    • http://klpa.net/userData/board/file/14085982422.pdfIn PDF document text
    • http://mcserpenti.com/userfiles/file/lilivifuxuxaxolivokevisi.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161378d388dd4f---26557830022.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/xuretatelavavudetevag.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/fawufebiriw.pdfIn PDF document text
    • http://ulrike-mayer.de/userfiles/files/39490319822.pdfIn PDF document text
    • https://familienbilstrup.dk/ckfinder/userfiles/files/39160056482.pdfIn PDF document text
    • https://cepatdaftargroup2.com/contents/files/wavanajisibezupi.pdfIn PDF document text
    • http://termosystem.pl/userfiles/file/97977506813.pdfIn PDF document text
    • http://vibrobreaker.com/files/files/kaliv.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/vezemixakavofupiwotadiku.pdfIn PDF document text
    • http://envigest.cz/upload/file/99603997165.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/64201394939.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c527.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC527 10888 bytes
SHA-256: 5b2ae71473c5979b3d670d03a1ebca649db5aef3279c2d76871176270e2a3fc3
font_01_sfnt_off0000de1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f62d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62D 18536 bytes
SHA-256: a745f75f45612a31032333026d4b86f3b18791cf6908c4c52f5447f01b0c4a49