Malicious PDF — malware analysis report

Static analysis result for SHA-256 856b7b8ae303afc5…

MALICIOUS

PDF

69.6 KB Created: 2021-09-27 04:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fcb217c63625b6c41f27239d6fbb936e SHA-1: 704d897b1ae2ed0c795732211beb640e83a22ae3 SHA-256: 856b7b8ae303afc57d61500cae3ed33509979312fcd543d726f6c55757a34d0b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

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://catamma.ru/uplcv?utm_term=talking+angela+hacker+eyes PDF link annotation
    • http://sungwoneng.com/upfile_editor/2021/files/xemizobirivavowipasam.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/tawawemexiberubomezozus.pdfIn PDF document text
    • http://csigikes.hu/admin/fck_upload/file/33389909915.pdfIn PDF document text
    • https://zerling.eu/nico/images/files/15471952765.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/gusituron.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/79049545534.pdfIn PDF document text
    • http://crimesla.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/8550455406.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/90100596980.pdfIn PDF document text
    • http://dlastudenta.org/Upload/file/puzukod.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/67336089303.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/32798998369.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411397a1535---43507588133.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138edc900f24---munuteforativukari.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/161466850a2c00---95540141854.pdfIn PDF document text
    • http://kondicionery-dzerzhinskij.ru/upload_picture/file/42299633305.pdfIn PDF document text
    • http://darslaska.org/ckfinder/userfiles/files/zidamujegijujule.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/wokali.pdfIn PDF document text
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/5506716220.pdfIn PDF document text
    • http://thetestmag.com/userfiles/files/54671274601.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efc3bd04e8---87906411802.pdfIn PDF document text
    • http://condosworld.com/abisol1/userfiles/files/98455830718.pdfIn PDF document text
    • https://webaprint.be/img/file/17195009821.pdfIn PDF document text
    • 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_off0000aecb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAECB 16804 bytes
SHA-256: edfa524f283adb4be5cfb5c8dba0caada160b8fd6767401b6c27293c57abc48e
font_01_sfnt_off0000d987.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD987 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19E 10460 bytes
SHA-256: c98f9d4164c13165ebd9d8c2f5a7cf4286d816c6ebde7a405aa9657ae53f9781