Malicious PDF — malware analysis report

Static analysis result for SHA-256 1e33c504104ef6e9…

MALICIOUS

PDF

94.5 KB Created: 2021-09-18 09:23:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cc52b5eae5b308153f49b24b1d5bab5a SHA-1: 93db23e3031b2bb31ed1d5d7f83a5bdff621086b SHA-256: 1e33c504104ef6e972d9268887e0aadde5dc1b37d736b39da52d8b48347b5202
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of PDF_JS and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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=android+vs+iphone+camera+quality
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/9a07b527ee2080ba900f8311934849b2/51795975808.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/127ego7l8po8erid5ov6pffk8p/betobebobekotadi.pdf
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/jufajipa.pdf
    • http://ekopaczka.pl/imgbrama/files/gureloviwalukoso.pdf
    • http://stilna-ya.com/_userfiles/file/16791492248.pdf
    • https://baglab.pl/galeria/file/27215190110.pdf
    • http://1mosref.ru/ckfinder/userfiles/files/buxet.pdf
    • https://cmottaviproductive.it/uploads/file/kijakotanepajedazenevu.pdf
    • http://shop-exclusive.cz/userfiles/file/febiwogu.pdf
    • https://saatyapi.com/upload/ckfinder/files/63466236782.pdf
    • http://velomagazin.hu/UserFiles/file/rikiwatokenemomobukekirob.pdf
    • http://mamnonhieutrung.edu.vn/ckfinder/userfiles/files/46433099617.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/c19a53a19c67ae069de3b3f83f2da2fa/riveputowijigozo.pdf
    • http://www.jacenter.org/js/ckfinder/userfiles/files/22059246994.pdf
    • http://raffaelecavazzoni.com/userfiles/files/9627391493.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/11iiocpcveb8kh5v089q6m2rru/67985409682.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369f9652890---gatonut.pdf
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377dc20bc57---razareditiwoviza.pdf
    • http://jj-metals.com/userfiles/file/2021090302110373499.pdf
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/92703367696.pdf
    • https://masini-de-ambalat.ro/images/userfiles/62769672041.pdf
    • http://rebornfair.com/FileData/ckfinder/files/20210913_C119A78FAF51A43B.pdf
    • http://jshanwoo.com/ckfinder/userfiles/files/palegilivadakabalute.pdf
    • https://siam-royal-view.ru/data/files/31623145428.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_off000106e5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x106E5 16792 bytes
font_01_sfnt_off00011ef7.bin
b56403407a18bb32850003af74ae4e456261e217bf3cb9666bd48f4c7fd10438
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF7 19648 bytes
font_02_sfnt_off0001520e.bin
943193ba4ec7935f195743efaf60c83f84144397558fb87adeba9c6848dac39e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1520E 11184 bytes