Malicious PDF — malware analysis report

Static analysis result for SHA-256 873cb55df215ba31…

MALICIOUS

PDF

76.6 KB Created: 2021-06-18 12:32:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4649270cefb9489f068edaa458a39fb7 SHA-1: 0b27921eb54b2af6dab25026bbc6e1a375ee08ad SHA-256: 873cb55df215ba314a0a3daec6f97d6d0ffb74a7c3aac990ca221a945634fa80
156 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be junk data, offering no direct clues to its intent beyond the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/89fe0cd546d4e561d748658bf8083e3a/muvuvaxulelowowele.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/6d3100e67f5d71b809ebbcfcb4b00230/97215970208.pdf
    • https://aarhuskortet.dk/images/file/69431216472.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f85704dbcf---zagukeg.pdf
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c2d5ed88fda---80468188719.pdf
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/nupimoxeb.pdf
    • http://falerisztika.hu/tmp/29497114322.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abea272c1d8---telegizobumixomad.pdf
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71019806518.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/infc5gghm4hkhgctfvf48sdc85/54705229949.pdf
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2d32e6aba5---61617585636.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160871bb240452---75728097862.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/gbtvroftdrs98aslukb002luk2/54254685863.pdf
    • http://churchontherockuk.org/home/churchontherock1/public_html/userfiles/files/towixunalefe.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/8dc719951ba631bc779f6641667619e6/fubobiwomeruv.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160705bcb53fb2---vujutatogewevimikemi.pdf
    • http://billsky.ee/files/file/vodig.pdf
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/e747a3a7b73764b44fe6d2188da32845/9914342200.pdf
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/e38b614834e43f95f42298a8040ea57e/22509327068.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=facts+about+ra+egyptian+god
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efa6.bin
8aa7dd5403b0ecfc7d69b2ac5efe5204e9fc900be314ae57cf2a102b9569f4fe
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA6 5404 bytes
font_01_sfnt_off00010216.bin
b7e1f4b307ed05d471993d131f579a7fe18348dfa17124159d1bcbbe7f7a1697
pdf-font-stream PDF embedded font (sfnt) at offset 0x10216 10304 bytes