Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb8d9b73ec2663b5…

MALICIOUS

PDF

82.1 KB Created: 2021-07-08 16:33:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c26321cdf0b208a5a1fce314f0652ab4 SHA-1: 41ecb9c4fa3832bd809b8168836ef0eb7e710709 SHA-256: cb8d9b73ec2663b50fcede9f97b4e06e37abbf995c74fb9bd919e12e7c3a6730
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. No scripts were extracted, and the document body was unreadable, but the URL patterns and heuristic firings strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://crysiq.ru/uplcv?utm_term=romeo+and+juliet+act+2+vocabulary
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081aa06433fb---vubobaxivazesegotul.pdf
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/gigisevebuzuju.pdf
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c218c3749ba---55367651764.pdf
    • https://afayl.com/userfiles/file/kuvuwawejekitivireluvo.pdf
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/8e0vtmcu8in6ouu07dsare1f8o/somizofutala.pdf
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/zepas.pdf
    • https://angelsstaff.com/uploads/file/46512753267.pdf
    • http://gfb.it/upload/fck/file/sosiwajiriwanedir.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a85d7445f0e---kinasofosaruwomajerirata.pdf
    • http://teraval.cz/res/file/50319387823.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/qerd5mrsr3alt6oacv55r4eq7t/nuvudovaxirowepigoxodezil.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab96dae4ab---55843505802.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc20dc5ef3---53792391704.pdf
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/5d28bb7cb95331203e7815c6ec3e344c/wulotetilomodunejamazeb.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/95c8a1cfef124aa14e513912d5b1dc2b/punepu.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/62610b5fb63a2bd25fe6444515d19edb/82287506717.pdf
    • http://baigeleather.com/userfiles/file/gofafa.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/6868100157a4478728113e831e52a415/98854423397.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e5d2f4f00d1---54577482224.pdf
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d63c005b6cf---45847113088.pdf
    • https://bikeid.net/ckfinder/userfiles/files/25495003346.pdf
    • http://gancza.pl/userfiles/file/88250676964.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_off0000ddff.bin
4a2b8a81d939a963978897e53137c3e645aceb93b04092208e33d9720c2ba243
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFF 16700 bytes
font_01_sfnt_off00010968.bin
da1461c948ec17045571e751cf3064a14a775366373f556d26394e8fce46e6b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10968 11080 bytes
font_02_sfnt_off00012337.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12337 16792 bytes