Malicious PDF — malware analysis report

Static analysis result for SHA-256 23c4c1e8d1213cf2…

MALICIOUS

PDF

75.5 KB Created: 2021-07-22 06:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8549e96687ad6180b6da605065033b7f SHA-1: b43d6030a8089c9959eb5a85c19577b31cc097b2 SHA-256: 23c4c1e8d1213cf2d37a669ea30551fabedba39b64524a08bf539029abbfcbc7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa7c1b9baa---75705659109.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/3fiv03octdts8s7cd3jv08jfk0/70527588649.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/e72080d53522174d372775c4c0d50093/tegakidonerasu.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/06tj87tcq7dq35munjj2l87lq0/fofomemota.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608804dc44b84---18014131835.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/at8q59teulu3vq39s40do9avg5/japokozegaw.pdf
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7747e57ab8---bawebaxipazanarexukaraw.pdf
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/4d91c0be5a13899a2fb6770714a7c875/kufalexasekip.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acec7bdfef0---82667426438.pdf
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/9850ab72a08b49f943844d16775f15a3/wifivozufis.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16078c26d40c8a---tawubegetotobozi.pdf
    • http://www.vegagastro.pl/upload/file/53779751470.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5f71422eab---38499100577.pdf
    • http://biosurfest.com/userfiles/files/vanalodejiraxele.pdf
    • http://hungbuloon.com/media/ftp/file/92238372669.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/628736b3b411481f9a5bd951049eff38/92425378411.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/7eae0701df31fb8facec2415fa7a244c/24023615991.pdf
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e5416863e---81171646789.pdf
    • http://classicalgardenornaments.com/uplds/file/42836879519.pdf
    • https://topupdana.com/contents//files/kafogofepoxamexefanemuja.pdf
    • http://sgyscom.com/upload_fck/file/2021-6-13/20210613170217406620.pdf
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/f7bdb7a4350567f22c1757677c89aa62/zasawavaguzirupa.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609691e2c98e3---10950802742.pdf
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/1b95fb17490c4951904a19fee8b7b45f/tenufemudog.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/9vk3orrv5dvmpsrgr5a543jsq2/zogopagowoperawabisan.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=what+is+the+lcm+of+8+and+32
    • 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_off0000c4c3.bin
07c0e827f73deda15e55169d481270b79be30f9223918c2a0a9dacbf24e96076
pdf-font-stream PDF embedded font (sfnt) at offset 0xC4C3 11132 bytes
font_01_sfnt_off0000deab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEAB 16792 bytes
font_02_sfnt_off0000f6bd.bin
38ca791d341708c7d2706ed9390c9726b809fab43d8aa7693b673476c2563adb
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6BD 15712 bytes