Malicious PDF — malware analysis report

Static analysis result for SHA-256 31f359327739a6d7…

MALICIOUS

PDF

88.3 KB Created: 2021-06-28 00:08:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 836de52455e943dc271bcd36725ec98d SHA-1: 0d9fd917e0972827f6bb02892d6047683c707ab4 SHA-256: 31f359327739a6d75c8aff15e273f9b5a2ef9652a2abc83ace1f46168bb7133e
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress installations, suggesting a link farm designed to redirect users. ClamAV detected this file as a phishing trojan, and the ML classifier strongly indicated maliciousness. The primary purpose appears to be directing users to external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/37jfmc4crjlkoh8ohrhlrdtc04/wewukujotima.pdf In PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160d21372587a5---lodada.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/b3fe97f8db55b0c256d0b78d15975ca5/befowujebib.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cee353e183---kebekawo.pdfIn PDF document text
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/66234846280.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/at9h5467j5eegehfc4ft3494h7/31439386635.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f04b0e0edd---52170025655.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c290de6c312---6962227490.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/76393006587.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8435f7cfa3---85677321106.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/c78d126eb6f20eaeebe281998e4623dd/seduduxovi.pdfIn PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/75977635061.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/2cad160fc0358f9f48d684fd3b48df73/gopuwikev.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/5700408461.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8fb5ea46e3---febobazowozifa.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/qdv3mpvt52q014ef10gjr54s8o/82179600782.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/ninumugotaxukexasex.pdfIn PDF document text
    • http://vestmorecapital.com/images/epost/sinozimijafulexoto.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160763240ad361---kenojeripezarem.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/kp7dov2gts0bhkkqabn2ke9tb1/47980460149.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-5-27/20210527234927349619.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/f9eda10b738187869dd46d1e1c9cd320/ravijapatubogag.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091420dd5c40---logewexanesibonijeramubu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=baaghi+3+full+movie+inPDF 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_off0000f78a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010fa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FA1 10688 bytes
SHA-256: 01567704cc34ef745ad9cd073ef4c8c04a6b96c6c9d3128751d412cfcc3c4542
font_02_sfnt_off000127fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127FD 16920 bytes
SHA-256: 075cc27ef3f6e20004cdbe8da66de6eab0989b571f860eb8d761c00a7ca3f302