Malicious PDF — malware analysis report

Static analysis result for SHA-256 15635d8cdd93e694…

MALICIOUS

PDF

85.5 KB Created: 2021-07-30 13:45:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ea9229e60e801bba4ad0ae476a224f1d SHA-1: c7ae62355ab52f079223428c6dc055a24e2b9779 SHA-256: 15635d8cdd93e694247cd66f080dacee7f37b4761c18b9e98b27c95d2f22d293
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating it likely contains malicious content or exploits. It functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting an attempt to distribute further malicious content or engage in SEO spam. The presence of external URIs and compromised CMS links points towards an exploitation or phishing attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://asckhn.com/acskhn/userfiles/file/tezevulawomabidizuz.pdf
    • http://digivideos.net/ckfinder/userfiles/files/vejamagopaf.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/43366ac6a44fb2a67d089c091993cd2d/67109927615.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/e72f066a3a6aa2ed21fa8906a4394428/xesugadofenadosobe.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f770b32f168---65506173641.pdf
    • http://ankurgroups.com/userfiles/file/31697915008.pdf
    • https://majorsagilekvaros.hu/uploads/file/lazat.pdf
    • http://begemot-rus.com/uploadfiles/file/2021062303145473499.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a792928ae12---xipabazipijazu.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b86d20ef7c4---zitunuxepiloju.pdf
    • http://wahluenfty.com/userfiles/fopujolok.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/bo72ubbes4fuqofbno4a8porll/susebipawosutinazofogurus.pdf
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/ae9533fef46103d0d278be59fd274ba3/zafapuzimuv.pdf
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/4a500755914b3804ccbd8a876613891c/76775007524.pdf
    • https://sunnyvale.com/wysiwygfiles/file/57950499766.pdf
    • https://przyklejki.pl/userfiles/55637729292.pdf
    • http://soles2walk.cz/data/file/fidisumot.pdf
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a1bc3a3c9bb---fizejaxilon.pdf
    • http://seritour.com/rsm/files/kinipasirelodogudifevi.pdf
    • http://hzzxtl.com/UploadFile/file/20210718004911371.pdf
    • http://mega-gold.com/userfiles/files/juponapivopewa.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa1dc7dab2---20085044838.pdf
    • https://thietbivesinhanhhuy.com/asset/files/lewulu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=dsx+access+control+installation+manual
    • 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_off0000e95e.bin
6c34d4328bca7833bbf3b179a3ea239cd3c44fa042e7074769e6850535414622
pdf-font-stream PDF embedded font (sfnt) at offset 0xE95E 17308 bytes
font_01_sfnt_off0001166a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1166A 16792 bytes
font_02_sfnt_off00012e81.bin
42228191d8b7f85aeff66cca0b7cca066f59ab69825bf14812e2e47599ea8849
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E81 10596 bytes