Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf809e252f770dc…

MALICIOUS

PDF

83.2 KB Created: 2021-07-08 03:10:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3231b4c1bf2cae627dd9cdf8c4eaabc9 SHA-1: 670a3e5f98a1c532e4517e46cbca316f449e7f6c SHA-256: caf809e252f770dc6b6648ff2ce8abe927a84f7bdcb57ec14d2a4c3f4a30af93
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://cructi.ru/uplcv?utm_term=effect+of+unemployment+in+malaysia+pdf
    • http://yournamebadges.com/withyourdog/cms_uploads/file/39914259602.pdf
    • http://alemotta.com/resources/original/file/5818097812.pdf
    • http://gymostrov.org/gymostrov/userfiles/file/vunosib.pdf
    • http://surausa.com/uploads/files/14645604434.pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba65dd37d3c---ninubajozumez.pdf
    • http://spc1962reunion.com/clients/c/c5/c535eb5d361035e84cedf1152ec4da8f/File/82595878121.pdf
    • https://bursac.net/userfiles/file/21969245605.pdf
    • https://coatielectronica.com/files/vumanasewobofabofadag.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083ca86ea8dc---potegutizidet.pdf
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/4735fbf90063f215e762d8b3d98c40fd/18883281236.pdf
    • http://autodilykanka.cz/cmsimple/images/file/fewokaguratiwexelilaj.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d271ecd6b5---juvibufi.pdf
    • https://mmszke.hu/files/file/15993868709.pdf
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098add4bfd11---kizetevexixifowalij.pdf
    • https://acronimocostanzo.com/userfiles/file/1786446925.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41898a9b5a---76505528758.pdf
    • http://viewcs.com/partner/upload/dextfile/95846649335.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160e3392738612---gedana.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/bhouiagu1g9rsomumaotqv1c5d/fofunalijusumomojeku.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1391e7f72---27070427855.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608778cfdd04e---misufegati.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_off0000e25b.bin
27477cb1440a3f89f78f7ebf47e3d8ad4fa6f060a014abc2c206a1b9490d185c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE25B 16928 bytes
font_01_sfnt_off00010e74.bin
0f2656cf6517a98eda01922ef3bb2dcf95abfd84dc0e6e080b591d3d94dfbea6
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E74 10880 bytes
font_02_sfnt_off0001279a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1279A 16792 bytes