Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57c08f1112e8e3f…

MALICIOUS

PDF

95.4 KB Created: 2021-06-28 00:06:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 645257d2083ec6dae4c91b5d8585d6a7 SHA-1: af6ed3f8d4df6d864201350331b9b0619ce89dea SHA-256: c57c08f1112e8e3ffe75fabd42cc3481009371f67a45880b4b6247b16bb21e8b
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised CMS upload locations and disposable hosting sites. These links likely serve as a distribution mechanism for further malicious payloads, consistent with a phishing or malware delivery campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/2100ac7058f170f21d7b44aa3a174ff9/wikukomavevaga.pdf
    • http://wami.cc/data/files/98214631754.pdf
    • http://astro2sphere.com/admin/images/file/16848137992.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba9e8b099d---38592956529.pdf
    • http://anjilh.com/uploadfile/file///2021050202294151.pdf
    • http://atol-res.pl/uploads/file/zoxiwobex.pdf
    • https://247hvac.ca/fabulous1/uploads/files/75286230482.pdf
    • https://bibliothequedesarts.ch/ckfinder/userfiles/files/kuzijokegewozek.pdf
    • https://baptistfriends.org/media/kejiduf.pdf
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160ac454d23a83---37177250292.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1a3805adcf---91828767712.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff2f6ca466---bimazuregobuwisa.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1607108a568b21---5503509631.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16089b53225306---talenuforowinu.pdf
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/3a2c97a0adb209b173cb8d4da42629a3/80041488997.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ca5c3ba0a---dobagaropelil.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e27fcc458---37017842276.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/7402748175.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/0f9953427364c8d1d7b95107da55f933/99562317004.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbec00db4e---27228110722.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff69a910bc---16650823309.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/pr90q1elppvo08vtqjlssbdqio/21008424720.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/nseeu01uqlt8q87itscje9scmp/nejabalot.pdf
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/ghumuvnhf0mubu5ilc6hdojqi9/66389767423.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=private+eye+detective
    • 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_off0001126e.bin
ec6765c1b3968a45d28788908e7d7c9b03ca81b73a0c4f3b91987cbeebbd2fd0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1126E 10108 bytes
font_01_sfnt_off00012922.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12922 16792 bytes
font_02_sfnt_off00014134.bin
a299f09f5f338af22c0db49a3cdf312c3429314e6029e582f6835dcf40926db2
pdf-font-stream PDF embedded font (sfnt) at offset 0x14134 18336 bytes