Malicious PDF — malware analysis report

Static analysis result for SHA-256 38b8668edd705c13…

MALICIOUS

PDF

94.6 KB Created: 2021-09-13 15:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b99c0174f0acdb8a1fa5139aea2e5506 SHA-1: 1ab87f5abd82ebabb2f57332f41f9298d209bcb2 SHA-256: 38b8668edd705c130836dfa87dba97d174f2ca9a760fbc15f73d00618e21953b
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Numerous external URLs are present, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious sites, potentially for exploitation or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://crysiq.ru/uplcv?utm_term=the+jungle+book+1994+characters
    • http://jljemc.com/upload/files/90735250578.pdf
    • https://mgogs.com/mgfiles/file/nanujaxunejoxof.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135acf3271bd---jibusuvugewatofoxe.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/ha3ru512mpa4mdi0dse69n5ikg/nazonetitifurefemi.pdf
    • http://optykglowacki.pl/obrazki/files/34700846380.pdf
    • http://hanboo.cn/Uploads/file/2021090501573370554.pdf
    • http://gulfcoastlist.com/userfiles/file/labuzi.pdf
    • http://seteo-dechets.com/images/file/87114575211.pdf
    • https://andana.us/files/files/31567212802.pdf
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8d6c0ac3d---28493301745.pdf
    • https://yesilkoyluleriz.biz/resimler/files/naxopitotijipuwepewibali.pdf
    • http://illinoislivestock.org/userfiles/file/woreminipemagexikesewuna.pdf
    • https://corpus.bg/files/fck/file/44010800513.pdf
    • https://foundationkuzmanov.com/files/vozigokepafevajowesebe.pdf
    • https://aquafilling.com/userfiles/file/72277166023.pdf
    • https://maxflowfans.com/userfiles/file/moner.pdf
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/kfgnjmm34dl581428u5pdcjbq2/33441349365.pdf
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/d4c7f8e8a15417241b3d52d973d1b3a5/392216772.pdf
    • http://cdseoulps.com/uploadfile/fckeditor/file/4755670517.pdf
    • https://karapinler.com/calisma2/files/uploads/89533022148.pdf
    • http://1-sanya.com/blog_images/blog_/file/fubeburogajeso.pdf
    • http://satthachkhe.vn/image/file/pugibevufiru.pdf
    • http://paulabenveniste.com/UserFiles/file/69584079240.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613237b8ecd62---ximuxuxorowizenonun.pdf
    • https://www.thc.gda.pl/ckfinder/userfiles/files/piwirivaza.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_off00010bec.bin
8c2d41152a155aa0a8ec28d16eb6ec3292268a1c73d376320ef922079b7c556a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BEC 11140 bytes
font_01_sfnt_off00012606.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12606 16792 bytes
font_02_sfnt_off00013e18.bin
462d0c51eef4884a91585ef067329163e07a090af6a15476bcf673562d975792
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E18 17812 bytes