Malicious PDF — malware analysis report

Static analysis result for SHA-256 d53f8cf6fc966c74…

MALICIOUS

PDF

71.8 KB Created: 2021-09-22 22:01:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c671cf0a8d92c0e5f99017170a4a87c1 SHA-1: 38d7018f1ff1b8ad0b7befb2bc0e04fd1de3fd0c SHA-256: d53f8cf6fc966c74abeaa6e8ba4818bf26838add3158f9ff011492b0f7076f34
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which are flagged as link farms on potentially compromised or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery. The embedded JavaScript may be used to further obfuscate the malicious links or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://grandhotelbulgaria.com/userfiles/file/28020859425.pdf
    • https://registracijakoncar.com/webroot/js/ckfinder/userfiles/files/90402362515.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/e3h8h5ioj4nsqugqk8jhf9pg0r/somamixapugam.pdf
    • https://sluganarodu.org/userfiles/files/biwetilevijufifusabiteti.pdf
    • http://www.ezmoving.com/file/zubipafonowusodipil.pdf
    • https://bdaudit.ro/userfiles/file/28251953769.pdf
    • https://cairparavel.ro/app/webroot/files/userfiles/files/mitoj.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612efc4cbfe66---89601844059.pdf
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/52469110941.pdf
    • http://affectif.ro/data/Image/file/24315911017.pdf
    • http://studioguagnoni.it/userfiles/files/netipakiwizidukurapifaji.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613f45284d60f---5005422665.pdf
    • http://diysmart.net/userfiles/file/jexizekiroxitev.pdf
    • https://triptoboloyfoundation.org/editorsfiles/files/93815424619.pdf
    • http://www.tomasjelinek.com/img/pub/file/32412752533.pdf
    • http://rootbeadmill.com/upload_fck/file/2021-9-20/20210920042206389520.pdf
    • https://lenaoyunlar.net/calisma2/files/uploads/sofujawaxiranup.pdf
    • http://akinmedikal.com/uploads/file/31232364939.pdf
    • http://veraschwemmle.de/fckdata/file/78470714236.pdf
    • https://pima-alarms.rs/slicice/file/57322646820.pdf
    • https://phuketwebstudio.com/ckfinder/userfiles/files/3954559580.pdf
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/15930815514.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=android+studio+arraylist+example
    • 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_off0000b5b6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5B6 16792 bytes
font_01_sfnt_off0000cdcd.bin
750e8908eb2ee396a202328eca0766c01ea49316c6b942e6b37ac5a284761434
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCD 10852 bytes
font_02_sfnt_off0000e6e7.bin
83a0659de6a7318a6ee9cc2388d97b63c835ca88989454178dc57f328afff8be
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E7 16296 bytes