Malicious PDF — malware analysis report

Static analysis result for SHA-256 c99f6dcaf80738e7…

MALICIOUS

PDF

69.1 KB Created: 2021-09-28 07:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4093925380142ddc5d21e3f27ecefb0 SHA-1: 064deb8bd53a4bf589ec8a89e57fbf2af9d9051e SHA-256: c99f6dcaf80738e78dcd31ed414c80d0685b7bf32edefb5cf59089c598dd6169
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites 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. The presence of multiple external URIs and link farm heuristics confirms the primary attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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=marvelous+walter+hawkins+lyrics
    • http://interstyle.org/content/xuploadimages/file/77588897699.pdf
    • http://gyermekhaz.hu/Content/site_images/files/86323144627.pdf
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b6504af3d---23906149464.pdf
    • http://jamalcar.com/userfiles/file/sovupixibigovagi.pdf
    • http://rvhifi.cz/files/file/2098263064.pdf
    • http://themadthinker.com/temp/vinney/HTML/userfiles/file/73702910758.pdf
    • http://fra2ange.it/userfiles/files/2478175340.pdf
    • http://metabolitplus.ru/files/file/19013873907.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613958b2d4b6e---nakonukigemunimibume.pdf
    • http://gachmenminhchien.com/media/ftp/file/biveravuwivolibe.pdf
    • http://bangkokmagnetwire.com/ecodev_test/image_system/files/90042264152.pdf
    • http://paitoonbox.com/userfiles/files/38405258032.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161373861a3465---52478502530.pdf
    • https://akrmedia.no/ckfinder/userfiles/files/ludelexi.pdf
    • https://sapsda.org/SapmaUserfiles/file/1959845510.pdf
    • http://rideabikenews.com/user_img/files/60983857074.pdf
    • http://bassbasement.org/userfiles/file/13487793774.pdf
    • https://thefencedocumentary.ca/adminfiles/file/dilobunewijiv.pdf
    • https://batdongsandothanh.vn/luutru/files/55251900786.pdf
    • http://nicolalazzarotto.com/userfiles/files/vitokafaxinanuxafevapeb.pdf
    • http://serbanindustrialconstruct.ro/uploads/files/72794782789.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614e25ae8441b---tamujuruwegewokofuven.pdf
    • http://praguetransfer.com/files/file/17762053188.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_off0000ad9f.bin
1f19d87cdcc24189b44b763552f0275ce48c19a7045755e3df08bb32a176a336
pdf-font-stream PDF embedded font (sfnt) at offset 0xAD9F 15220 bytes
font_01_sfnt_off0000d438.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD438 16792 bytes
font_02_sfnt_off0000ec4f.bin
2968a5d45566104d1e9230d1910e6b37311bc9e0ee813fa138bac24ad75f2363
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4F 10776 bytes