Malicious PDF — malware analysis report

Static analysis result for SHA-256 785f16a3f903bf38…

MALICIOUS

PDF

82.2 KB Created: 2021-08-23 09:45:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b67618752b64fa5e150aa8bb40ac2c79 SHA-1: 1e6c3e8993379b8d0133bc4b75b06ef7926c577d SHA-256: 785f16a3f903bf3862e4d97429cccf503acfec175e02124ee2d6ecb59b356177
156 Risk Score

Malware Insights

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

The file is a PDF containing a link farm, as indicated by multiple heuristics and extracted URLs. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of numerous links, some pointing to compromised CMS uploads, supports the attack pattern of a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://annjulieskarpmo.com/userfiles/file/88302364774.pdf In PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/4114092202.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/77055209865.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160d20a79aef71---71592199233.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/gatisipopodudalokow.pdfIn PDF document text
    • http://aahsclassof1978.com/clients/b/b6/b6117739535924054831d33ecd54b00a/File/gewupubifigukutoxo.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608b01f5c48f2---52820803944.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/0bk4ldpb1vvqqmd3qo5f9lr7f0/tomesokisoboxi.pdfIn PDF document text
    • http://mamitobe.ru/files/file/86726266221.pdfIn PDF document text
    • http://drtamerturan.com/file/97696105628.pdfIn PDF document text
    • https://vansuloi.com/uploads/userfiles/file/42044465019.pdfIn PDF document text
    • http://ticaproduce.com/ckfinder/userfiles/files/xasebemogifezam.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/11412614483.pdfIn PDF document text
    • https://machnhaduong.com/images/uploads/files/6747180025.pdfIn PDF document text
    • http://forumcutuca.com/ckfinder/userfiles/files/sukik.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/39873753791.pdfIn PDF document text
    • http://alpha-th.com/userfiles/file/mezadapiku.pdfIn PDF document text
    • http://cascinamana.it/userfiles/file/livov.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611736bc3a86c---34078910211.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607997203d341---1062925400.pdfIn PDF document text
    • http://futuralagoparking.eu/userfiles/files/vaviru.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/36613714496.pdfIn PDF document text
    • https://argumentua.com/i/file/7531975206.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=deliverance+from+marine+spiritsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000def9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF710 10708 bytes
SHA-256: ce8cd943fb6367b4b72d04b2d7778111ea26ef6cd8c64473a4868fc368b40eb6
font_02_sfnt_off00010fa3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FA3 16836 bytes
SHA-256: b392c44cb591a3d0865b0fe6137db237e3683e1bf26879a15af16b5e2b0fb679