Malicious PDF — malware analysis report

Static analysis result for SHA-256 b64b4b56da66f121…

MALICIOUS

PDF

85.7 KB Created: 2021-06-26 07:54:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e050b4b0b8a6fe71198d2755a9a9ebcf SHA-1: 9f6d4fc69fcea72b6efd3c460a5c3b87e69b693f SHA-256: b64b4b56da66f121966f3a5197f603f6fbb237353235f789ea6cf44b9dd0cf42
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised WordPress sites. These links likely serve as lures to download further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/d40b1bb7f155951889698f0cfcf13dad/31637626599.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a06eb8660---34038712507.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/b2um1s43askc0s0cf19fqj9r3e/1348360043.pdf
    • http://apvn.info/userfiles/file/78141470616.pdf
    • http://baovephuongtroi.com/vietkiendo/upload/file/15529153158.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3b8653b34---mulopodu.pdf
    • http://tsg-edinstvo.ru/userfiles/file/18441966952.pdf
    • https://isleo.com/i_photos/file/80012558097.pdf
    • http://shinies.ru/img/lib/file/19384228317.pdf
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/kcq236m99vlqkc2u64008uaqa7/57644683083.pdf
    • https://studiovizia.com/webroot/img/content/files/gemumimo.pdf
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/16094958ccfe76---fasoketevoj.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160cbd680aa0e9---63980581093.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/59cfda189e4f79170b142ef36facfa8d/tibudafikamupas.pdf
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/f2ecf49e5a3436e7bacb5060e6ae9be3/pexolokuzopivuber.pdf
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/e9e2772130d31c2106824d42d512e129/suxekajawobado.pdf
    • https://andrejc.si/files/file/noposivoz.pdf
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd970def9cf---26085357902.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/4d76245fe795ab10dedb687be4a9beb9/wikataputakumur.pdf
    • http://aelma.com/sites/default/userfiles/file/kakirabebarafow.pdf
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd0e117f26---zufebonesabesorekivitonu.pdf
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a414c8a70f8---17790129272.pdf
    • https://sluganarodu.org/userfiles/files/basanemaxarojin.pdf
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16093fcc641e8a---20121644420.pdf
    • http://hk-dcc.com/wp-content/plugins/super-forms/uploads/php/files/tmemuoukgns6g5rhmjfdlag2k7/winep.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=cut+you+off+meaning
    • 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_off0000eb4c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4C 16792 bytes
font_01_sfnt_off0001035e.bin
2b6abbaa93c6994a1f41b9aeb0acaf21dc148a57deb78275a97862994a02a595
pdf-font-stream PDF embedded font (sfnt) at offset 0x1035E 17808 bytes
font_02_sfnt_off000131d7.bin
73ebf76dadc0904857624c1f6ae9b3a9163911c77e9488dec5ac046d55c8aa9d
pdf-font-stream PDF embedded font (sfnt) at offset 0x131D7 10488 bytes