Malicious PDF — malware analysis report

Static analysis result for SHA-256 57a611bdcce76cce…

MALICIOUS

PDF

72.1 KB Created: 2021-09-27 14:53:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2f2002576004a61ce58bedb6cfe6e5cd SHA-1: 7386b7843fc8e6a5f461235d44857e76aa7515bd SHA-256: 57a611bdcce76cce5c38eda701a44c29ee7019cea168de70d41ca7efdc5c72e4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Several URLs point to compromised WordPress sites and potentially disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://crysiq.ru/uplcv?utm_term=san+andreas+game+apk+download
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/1397126e4c5085b88c231952cbcc6fc9/73153664667.pdf
    • https://newtop-eg.com/userfiles/file/vuwovazi.pdf
    • https://stka.gr/ckfinder/userfiles/files/legewuloriroroduza.pdf
    • http://pngroup.pl/ckfinder/userfiles/files/78925266435.pdf
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/87f648b16ef0a1b60d35cc631d25713d/40554681238.pdf
    • http://fotografiafrancescosomma.com/userfiles/files/vozesekiboluwofesejexu.pdf
    • http://aliguoriarchitetto.eu/userfiles/files/pugininetezilobozigufosuj.pdf
    • https://lordoptika.hu/files/files/93861500445.pdf
    • http://szentistvanpatika.hu/upload/file/31623582496.pdf
    • http://thetestmag.com/userfiles/files/51115237507.pdf
    • https://mn-lawfirm.com/box/userfiles/file/76313972273.pdf
    • http://recko.ru/ckfinder/userfiles/files/jazimatabe.pdf
    • http://leeandrewdavison.com/download/33024681395.pdf
    • http://okun.su/upload/file/fuwobenasatidokawufujoxo.pdf
    • http://creptiles.dk/userfiles/file/547442792.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4b8e27063---65853534841.pdf
    • http://coeb.eu/userfiles/files/51738548775.pdf
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/7c6fa1034c01cc751fe2a54eff53d899/tameraxi.pdf
    • http://nenorm.com/files/files/jebetumuzevo.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dec08c08f8---bexobidavalobasanok.pdf
    • http://sedaciesupravy.sk/media/file/digijarar.pdf
    • https://ladulceseguros.ar/noticias/fckeditor/file/zuweguwu.pdf
    • http://h-st.nl/bestanden/files/43745154709.pdf
    • https://wintechindia.in/ckfinder/userfiles/files/68875131245.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_off0000b402.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB402 16792 bytes
font_01_sfnt_off0000cc19.bin
fd434bd378b38ff27a7f767a27505ac1b1c2feb1561f33496c38b8a484037a95
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC19 10800 bytes
font_02_sfnt_off0000e4c5.bin
4f7c3cfb158f7e0bfd7c6dfb55dc4166d9184d29eb08b51bbad8b0e1defeef96
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C5 18200 bytes