Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6ab803c2bb4b56c…

MALICIOUS

PDF

79.1 KB Created: 2021-09-16 19:18:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e73143e3aa4be3b9ee8d8949bb76337b SHA-1: 2992da4feda33e2a5f75fe973c998652238f8a9d SHA-256: b6ab803c2bb4b56c05ac877195a572dbdf2615481642e68185d744ddfdf6d84a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many external URLs pointing to potentially compromised or disposable hosting. The presence of embedded URLs and the nature of the link farm suggest the document is designed to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://reanda.com/jingkelun/userfiles/files/20210903170121.pdf
    • https://www.nbc.com.vn/ckfinder/userfiles/files/66895365029.pdf
    • http://paddockj.com/user_data/editor/ckfinder/core/connector/php/upload/files/91844614706.pdf
    • http://k9careclinic.in/ckeditor/ckfinder/userfiles/files/88531576464.pdf
    • http://omni-links-europe.com/images/blog/file/29340135645.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b70008862b---89163079288.pdf
    • http://dragonspond.com/uploads/files/supawuxaxinoraberowoduko.pdf
    • https://kuepancong.com/contents/files/3379914109.pdf
    • http://aisne.proximeo.com/ckfinder/userfiles/files/nifinatodunonidisotere.pdf
    • https://auditorescr.com/ckfinder/userfiles/files/37992553863.pdf
    • http://vector-mebel.ru/uploads/files/bokojuzajogoxovefasinujep.pdf
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/pixewofipow.pdf
    • http://schokoladenfontaene.de/idata/nopajuditiregelosur.pdf
    • https://eijo.in/ckfinder/userfiles/files/10075408297.pdf
    • http://samwha.com/upload/userfiles/file/17672115244.pdf
    • http://canshu.dlzj.net/upload/files/20210910205816287366.pdf
    • http://studioassociatoemc.com/userfiles/files/62334224022.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613662f737f7b---6279080166.pdf
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/6f7960751ae36c1b39db035580f4a1e3/81502975473.pdf
    • http://masan315.net/board/imagefile/file/fekamonanilagotibalo.pdf
    • http://dezis.ru/uploads/files/56768832127.pdf
    • https://latrinquette.com/upload/editor/file/54837164398.pdf
    • https://maffart-guy.com/userfiles/file/nelilor.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=free+convert+youtube+video+to+mp3+on+android
    • 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_off0000d0b2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0B2 16792 bytes
font_01_sfnt_off0000e8c4.bin
35a3255ac3b8c6fadd55728f271f74afdef031068cc64fc82102eb11d45d9625
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8C4 17344 bytes
font_02_sfnt_off0001154a.bin
c55586dd1fd1f3f0499c4275f48502d21e8519bad2fd2af9fb5322c5fed99934
pdf-font-stream PDF embedded font (sfnt) at offset 0x1154A 11028 bytes