Malicious PDF — malware analysis report

Static analysis result for SHA-256 9809780bc90f1829…

MALICIOUS

PDF

82.7 KB Created: 2021-09-15 21:23:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 839a4be8d31076caeb7ef9bd50169d10 SHA-1: 5bc0bfae7902ac05404d31aa58cc9b3b2c3c8cb1 SHA-256: 9809780bc90f1829bdc3239cb1df6dd997efb9eec58227b3fa65343250a3e6a3
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with 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 distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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 https://inwebjor.ru/uplcv?utm_term=zello+android+wear PDF link annotation
    • http://ccforum.kr/uploads/file/1631444351.pdfIn PDF document text
    • http://ipai-bg.eu/img/file/91551478123.pdfIn PDF document text
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/66261298699.pdfIn PDF document text
    • http://icoenergia.com/userfiles/files/41770608770.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/vufujuge.pdfIn PDF document text
    • http://alltechsro.cz/files/joxetuxidibakeno.pdfIn PDF document text
    • http://free-note.kr/files/fckeditor/file/473673487613d53a3ed98b.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/b2dafc5ae346424cafe111d2f6966cc4/43461012805.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/kajatotatetorizuvon.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/16916115173.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/rqiacvd5s9c7c0ij70ulpqju72/setumedi.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210914180509.pdfIn PDF document text
    • http://synhbio.com/upload/files/16585651075.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613388fc2fdab---risilemog.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/8937368188.pdfIn PDF document text
    • http://nenkin-t.com/upload_img/ck/files/8578693778.pdfIn PDF document text
    • https://gkia.org/kingkong/userfiles/files/42069806606.pdfIn PDF document text
    • http://ipceurope.eu/assets/file/14561968492.pdfIn PDF document text
    • http://commsoft.nu/demo/ktb/wsmbilder/files/kejexapitesetixinedirato.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/59685448581.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/19141934264.pdfIn PDF document text
    • http://chinahk-ip.com/chinahk_ip/html/files/editor/file/puwarefudedoroxusovi.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA23 10024 bytes
SHA-256: 8e3f2cff616cbce666b9c30ad95b0ef2aa9e90e0a571df3f505b05ef61a1f667
font_02_sfnt_off0001107d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107D 17468 bytes
SHA-256: 26fc9a12ef33cd9b0b029417d2d51a489bd699070837659bfe3925c74d221044