Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8551786241857af…

MALICIOUS

PDF

123.1 KB Created: 2021-07-01 11:44:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: dd1f3617cecd119efd650f0c46b28056 SHA-1: 803789ced4de4994c78ea92ba6e3a5fc796b4243 SHA-256: a8551786241857af308b65d9366eb16a5800685fd2858603faa447552988b80e
176 Risk Score

Malware Insights

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

The sample is identified as a malicious PDF by ClamAV and an ML classifier. Static analysis reveals it functions as a link farm, with numerous embedded URIs pointing to various websites, many of which appear to be compromised WordPress installations. These links likely serve to redirect users to malicious payloads or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9161

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084352f12e4c---xanedobinisesabukir.pdf In PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/160839dee541f5---62081913677.pdfPDF link annotation
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160972030a35c0---37498416823.pdfIn PDF document text
    • https://hoangnhataudio.vn/media/files/15359514394.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/cde4a0f3a806756e5ef05bd86cc47af6/44465707726.pdfIn PDF document text
    • http://cnpair.com/userfiles/file/buxovusonaranubi.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a450cfd85b9---kebafu.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1608256f9299d1---logalowivajupitawemidixug.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4cfda1574---71818630276.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/gumizidiwelumar.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/63ebd9beb336a1c135f993e1040c8d85/35351161616.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/botaxif.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/79931184458.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/fazavekufazolawafeb.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adb198be15a---zipuzaxifagogetodamajuxi.pdfIn PDF document text
    • http://mobilenmr.com/files/files/xivezesipoko.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/23707092732.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/1fdbpdlrv4canoc4kuijvhk3f2/29309864470.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/3eacc3ce56f0df0da5feebeb68ebf3e0/fubuf.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/df5bb980b57475ad18c76ae494a1dcad/49620284974.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/clr8dfgak3rvog20r4t957c1d7/tuvatipoburixejumusabax.pdfIn PDF document text
    • http://snsi.jp/image/news_file/lotazafifu.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073272b0966f---nixulexip.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a264cc1675e---pewupitulotoman.pdfIn PDF document text
    • http://cyuanmei.com/userfiles/file/87830867371.pdfIn PDF document text
    • http://africa-emergence2019.com/userfiles/file/revuromazozikeko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=i+long+and+short+soundsPDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013393.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13393 16544 bytes
SHA-256: ecb6d4fd825ef07e9b532c5d35f75aefa54a961a965e81ff77057b86e0507170
font_01_sfnt_off00014acc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ACC 30516 bytes
SHA-256: 5f78c27e83acc33a2afa71e8358195e969f0a4c2de0840e437b615dae2a330d3
font_02_sfnt_off0001987f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1987F 10356 bytes
SHA-256: 2f27c2136b31ba33c41ad3a940c17c1d465a82a265bb6389e88c471a75a22a02
font_03_sfnt_off0001af9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AF9D 6212 bytes
SHA-256: cdd5a9f113a9aa2920e37f64a0803e768737fd409f6fa66058834af1e5579255
font_04_sfnt_off0001c5df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C5DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1