Malicious PDF — malware analysis report

Static analysis result for SHA-256 58ac33d3eb4c2b66…

MALICIOUS

PDF

88.3 KB Created: 2021-06-25 13:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: fb30ff8d6eb7129982320276e4e7d28a SHA-1: 89b624571ef730ba5ebc24f42d1ef1b3985cc1b8 SHA-256: 58ac33d3eb4c2b6682ae917908271b23cefd0c6cc3e04c2b4851bf6b63936de5
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised websites, many of which are hosted on WordPress installations and utilize form builder plugins for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to download further malicious content or to exploit vulnerabilities. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 6

  • 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.
  • 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.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b89a4d7f2f0---75415299070.pdf In PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b980f340131---13713285002.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/vl82li8m82a0i8jutq1l0558ic/56656306636.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/171b89c63d640498040707436f3eac49/duvinamazaluginerivuxikun.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c76b0bb2abf---31543508270.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5763811cf---34524894637.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2275a73fd0---85323544978.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a31cbfbf3dd---volelanudim.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/lizumadizogefupi.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160945ea70f652---dadobama.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/22427628385.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/51dd0ad649dc1d1b15d2a38a94e38bed/72888976558.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/nspoq7gi8j15oobqg8fnes2js1/98293558468.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1c42769671bf298a16bbd98ec0921154/59683054319.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=the+rainy+day+poem+answersPDF link annotation
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000defe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFE 18112 bytes
SHA-256: 9dbd67eb6f9bbc2e7865d75a44020badb137d0d835d3e1873a379bced913c634
font_01_sfnt_off00010e97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E97 16164 bytes
SHA-256: fd494554c7a7a2c4488382a78096c535ff133766c7221992be4f6a58596b2467
font_02_sfnt_off0001240e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1240E 10676 bytes
SHA-256: eea2453df769a3fbeb1872644e9da56a233c707a3037ac13abb8d2a6db9776cb
font_03_sfnt_off00013c60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C60 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1