Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ca20295a26567b5…

MALICIOUS

PDF

82.7 KB Created: 2021-09-16 00:59:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65894ee664c34346f0ef089f5f7860cd SHA-1: 28191ce6e0124b53cd1de77e2d4d2262af35fc0b SHA-256: 8ca20295a26567b57e3422ef30b515e027cc28bc46687b921e7f6e6db79daa03
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for executing malicious code within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=smtp+relay+office+365
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b4d7bb1a4---99897125667.pdf
    • http://joy05.com/_UploadFile/Images/file/kavojaxekeri.pdf
    • https://optical-axis.com/uploads/files/202109010432435658.pdf
    • https://nergizleryapi.com/image/files/gusiniruxoginidosovixujan.pdf
    • http://longruiglass.com/ckfinder/userfiles/files/20210913_235855.pdf
    • http://sangjeom.com/userfiles/file///37470166619.pdf
    • https://ceccarmehedinti.ro/userfiles/file/99417437548.pdf
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613775837c5c5---mamumu.pdf
    • http://jinyezi.cn/upload/17740913088.pdf
    • http://docando.es/js/ckfinder/userfiles/files/34826663601.pdf
    • https://kaktutzhit.by/uploads/files/67634638325.pdf
    • https://xosobacninh.vn/webroot/img/files/21874777215.pdf
    • https://vadihosting.com/calisma2/files/uploads/tofuvapafifaler.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1612edd2615f46---batamabepufejofi.pdf
    • http://bigbazar.cz/is/images/FCKeditor/File/5937392874.pdf
    • http://fantacyhandicraft.com/userfiles/file/65672943365.pdf
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/61565krtslee09utpg9a5dmr60/firijesexez.pdf
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/kobizujepuzamifu.pdf
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/60342055544.pdf
    • http://lesbambousbleus.fr/ckeditor/upload/files/xegotunetamup.pdf
    • https://chameleoncoupons.com/adgprocessing/uploads/files/77502004591.pdf
    • http://reelproductionshd.com/userfiles/file/45543032316.pdf
    • https://wheelmartthailand.com/image/upload/File/61488190139.pdf
    • http://leprofit.ee/cmsfile/contentfiles/jujififulanatojafejolamus.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_off0000dd73.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD73 16792 bytes
font_01_sfnt_off0000f58a.bin
4535f5d14a19d60a1f8c4a260f9f0b3e404c314c5cbf128133fe48eb45f62b25
pdf-font-stream PDF embedded font (sfnt) at offset 0xF58A 11032 bytes
font_02_sfnt_off00010f46.bin
088b0d94b16b0ae4dfd9800b942b19ef3ff8f9181a00928f0f02ccd18255e9b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F46 17808 bytes