Malicious PDF — malware analysis report

Static analysis result for SHA-256 a930c16a5d2400aa…

MALICIOUS

PDF

88.6 KB Created: 2021-07-22 13:01:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0ef6d675659215e7de908e3774e28c2e SHA-1: 72c45f0b1671ea768307ef25d01864b786700b21 SHA-256: a930c16a5d2400aafa0b9974b7ccdac952421a78a9273b65c838f7c9e1cc342c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a significant number of external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e840015504---pesofuz.pdf
    • https://empezo.xyz/js/ckfinder/userfiles/files/lajefalofoxuvunum.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/b92119134e31efd829a523437c408f2f/4520014577.pdf
    • http://atut-biuro.com/uploaded/file/jajifusowuwuzemo.pdf
    • https://pasarantogel2.com/contents//files/buratamugas.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a72d7ea2c11---59897366758.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/ui16c5rp2ei5ikkjm47edrq7qp/lovaxofotemurili.pdf
    • http://ingegneriarossi.it/userfiles/files/88429743645.pdf
    • http://xn--or3bi2da319p.com/upload/fckeditor/file/38418541649.pdf
    • https://ndmoyun.com/calisma2/files/uploads/fotojaxaxuteragexuzaf.pdf
    • http://faradtvandor.hu/picture/userfiles/file/93968109681.pdf
    • http://lroundup.com/clients/d/d7/d7466da0ad72d96b64793f89c518a0d9/File/12949865682.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb304a39f8---xafipeg.pdf
    • http://thebestpearsonfamily.com/clients/e/e6/e6a49a9b6fa3fb0349b1957bd02e8b5b/File/vibopapi.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160adccf481666---vunerowiduxilape.pdf
    • http://iaestedresden.de/userfiles/file/paluramodupawup.pdf
    • https://himanshikitchen.info/viking1/uploads/files/45917213591.pdf
    • http://kayapaliinsaat.net/file/92736122635.pdf
    • https://www.travelknowhowscotland.co.uk/assets/js/ckfinder/userfiles/files/levowavekuxubozanula.pdf
    • http://chi-kara.net/Upload/files/nakedegop.pdf
    • https://migger.dk/userimages/file/60529357345.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/06e4bbe059dafc3e39a04136076d199d/loxuzusafegate.pdf
    • https://k-barrierfree.com/FileData/ckfinder/files/20210709_0D81AF1B7930EC1D.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a350c5d9c9c---dazowizesigolekuso.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/16070fd4b25090---42856280866.pdf
    • http://lookkorea.net/userfiles/file/23612523259.pdf
    • http://dfh-consulting.com/userfiles/file/37475789605.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=energy+transfer+in+biomes+worksheet+answers
    • 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_off0000f838.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF838 16792 bytes
font_01_sfnt_off0001104a.bin
539245234ef7e4256e1cb46a5c2ec6fcb5eca6332c285dc5240a40fa3a40649e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1104A 16304 bytes
font_02_sfnt_off00013a74.bin
c3ba132125208f411ff0ede2be26607c8dde6b5f241325cc5d106556949aa1e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A74 11028 bytes