Malicious PDF — malware analysis report

Static analysis result for SHA-256 31af09c922b781f5…

MALICIOUS

PDF

87.8 KB Created: 2021-06-27 15:10:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: db575dd19a490a8e56b76f099eb66c79 SHA-1: e1d8f3cb079a424eb84fb4870313c325b67a78c0 SHA-256: 31af09c922b781f5fc8031ceaf9779a9de81a37a11fa33a62734ec0be6d45854
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure as a link farm suggests an attempt to obscure the ultimate destination or to leverage SEO poisoning tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://xinyuemu.net/assets/202106/files/20210623195644168621.pdf
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/c4c63e287588dba531985add8ed06ff3/7394701222.pdf
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/u2gni5gjs6pkt3al1snu8g0fl6/gisapib.pdf
    • http://aryajob.com/user_upload/file/junijafodupuje.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/b54b7437d2b486e2785a875afbb86355/54636384121.pdf
    • http://royalwedding.jp/images/blog//file/kimitekovadifaramarolurel.pdf
    • http://nfraccon.org/userfiles/file/56184884474.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/l387008eheeg1r95ubub7ivj74/zopojabuxowikul.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b95bbfb0e3f---vejefonimeligedetedipa.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160adc845312e2---34980104050.pdf
    • http://bliksis.ru/userfiles/file/mebutexu.pdf
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/zugedoxipulosarebuvib.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d76c3726af---xajigedorezavexipinowo.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/9jr0mtf2uq247jk4bhihm420j7/74071387065.pdf
    • http://videofilm-tv.ru/content/File/97956705680.pdf
    • http://tovicetour.com/FileData/ckfinder/files/20210618_874E28A898128454.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/1kf06sjcrd92fd9ndgphkqna21/48461166658.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/a5c5e2b2bbbd41fb9cc43e555e42ac41/28402220703.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5cefc147cf---karulogukewibu.pdf
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608599f3d7576---87170013569.pdf
    • https://stillwaiting.org/userfiles/file/kodelidut.pdf
    • http://rurisnet.org/images/file/20443257685.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a34a35aca7c---22588938717.pdf
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/8cf56359f3cf0cae84e87d4cdf15155a/ximumub.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/45sn9lus23jo0jkmlj6dd4f628/67077123591.pdf
    • http://allprintusa.com/admin/images/file/tonosabujitibolubox.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=neutrophils+high+means
    • 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_off0000f302.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF302 16792 bytes
font_01_sfnt_off00010b19.bin
e20c3763718d412dc4f6dba3c7257a512c0957cff4e7f1afe4415cf1ed66c834
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B19 10776 bytes
font_02_sfnt_off000123b3.bin
9677f1e87b9991738ecfd5491e51b3d9abcd2cdf6e84f98040bedba4795205fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x123B3 17308 bytes