Malicious PDF — malware analysis report

Static analysis result for SHA-256 31ebcc6e84d85332…

MALICIOUS

PDF

92.7 KB Created: 2021-07-17 22:44:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 54284f3f22c2e480234f045e0aebe184 SHA-1: 34ea3367f4c5a2cbd17348cac0029602d169c03c SHA-256: 31ebcc6e84d85332e26400fb086e1bb8fb142ec937cb4273d69b615adca9a1a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad65c1b69d8---suvavapenutazigosemoravi.pdf In PDF document text
    • https://mmszke.hu/files/file/kolofamovebawojeko.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce73938e19b---xamolerojumozegax.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lujilesaribasapilobozifem.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/wojexafed.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/44815987079.pdfIn PDF document text
    • http://rghsalumni.com/clients/82979/File/25001967542.pdfIn PDF document text
    • http://energo-market.ru/sadm_files/27886001449.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/sunezegodukuxadebe.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/6135946ca445c68f1ffea73538addd52/62398875418.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/0f5fb55b3b4e26eea4bedc49d7ed9d26/11559707059.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef15919d14---tilubibovaj.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609695e55c95b---13144293039.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/woleposiro.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/30452610275.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911246d90db---dogoxaduti.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160bda92dcdba9---memibilawamovulopomu.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160d33d6e0772d---rejofotagiz.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cae81d01fd---lowonilafugebuxuluzelat.pdfIn PDF document text
    • http://wagnerpc.com/userfiles/files/razulikalizovoveroxamovek.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/00uu23eep95qc9uvnun5o8ls2k/kuwesobagex.pdfIn PDF document text
    • http://uctodane.cz/UserFiles/File/bujasofawu.pdfIn PDF document text
    • https://go2germany.ru/files/file/mipafivurepubirebumezif.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc9f0855c05---rabikinikavuja.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=do+other+animals+have+an+appendixPDF 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_off0001094a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1094A 10828 bytes
SHA-256: 0a5be30c5669447c8d64552abc739917fac7039e3ae2eb62dad8a94777495934
font_01_sfnt_off00012213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12213 16704 bytes
SHA-256: 8b31f44dd063271a4bf1849f2a1ed1b6c22137c45b667532be93640b1ca919a0
font_02_sfnt_off00014d5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D5C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1