Malicious PDF — malware analysis report

Static analysis result for SHA-256 0557b411c6b6c00d…

MALICIOUS

PDF

92.1 KB Created: 2021-07-15 14:48:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 172e475b9bd138e61c326eae70cc9ce3 SHA-1: 6d1a307cfb9d44a7d7b67dc3fe93079a95de671a SHA-256: 0557b411c6b6c00de7780ef54adbc2f49550448b4fadaaee0e277dccb74c7e9d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, and exhibits characteristics of a link farm. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The presence of 'utm_term' parameters suggests an attempt at SEO manipulation or traffic redirection. No scripts were extracted, but the PDF structure itself is designed to host and distribute links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://pistant.ru/uplcv?utm_term=ielts+reading+practice+with+answer+explanation PDF link annotation
    • http://architetturaurbanistica.it/userfiles/files/29089561908.pdfIn PDF document text
    • https://tkquiz.com/userfiles/file/fugure.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/9097318836.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8bc816b1c---leponuwetas.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/84091425526.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/81470433403.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/96371428805.pdfIn PDF document text
    • http://leilehua76.com/clients/4/4d/4d80c013f15dbe3c797666a457780dca/File/73722134505.pdfIn PDF document text
    • http://singer-island-condos.com/userfiles/files/gamopuxupelowotiz.pdfIn PDF document text
    • http://sillajen.com/fckeditor/_upload/file/98330359171.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16097325f38d2d---2804328768.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ba521c326d8---suwoborev.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/1c7be40833bdbd35da5158da71859e52/5007095189.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b07534369---44607283914.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/goworibin.pdfIn PDF document text
    • https://hse.tw/upload/file/60279006943.pdfIn PDF document text
    • https://advik.net/userfiles/file/zenabelesagokamun.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c40d7caa5d9---zereruxezutek.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/83e8d2d6d4e4219afc270a55745019d0/folekiwugokesezivejoz.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/nuteragubawabexapixibu.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/loparozogunavavuboziki.pdfIn PDF document text
    • http://tate79.com/clients/868750/File/22871972716.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/6cbe57692aaedef3f92be7d8ece9a11b/54761731460.pdfIn PDF document text
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/f8b59af0cc053fae6210542b17d65a1e/mokexol.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_off00010616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10616 10932 bytes
SHA-256: b5f63fcc594e1a72201db9564914487c3b9b8f67c56c1f18e060aab7824d76e8
font_01_sfnt_off00011f38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001374a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1374A 16728 bytes
SHA-256: 10d668f596ac2686eee943df31b8b49df2ea9905821e44be3aac4f6dba84fba2