Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b4dd8f685255f7a…

MALICIOUS

PDF

76.7 KB Created: 2021-09-02 05:34:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 4a96870e846fcb357ceb95ea2619dd75 SHA-1: 75adcaa05e4c84feca62c6eb251f9703948c3d7f SHA-256: 9b4dd8f685255f7a8aa3fe818ad0ded644a9e63cb586d3a5120e3e94d1368144
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and uses an image-based lure. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 76 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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 http://www.wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/rudagoperojafovijifufo.pdf In PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16092d191953c6---sovubode.pdfIn PDF document text
    • http://atomleasing.ru/media/File/gekikekemebapofekixa.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/51acf720d87d8e64bb9ee9f594552b19/rusatuf.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160832edf29dc9---37756253006.pdfIn PDF document text
    • http://nguyenquangcomputer.com/upload/ck/files/1387495431.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/25146820223.pdfIn PDF document text
    • http://tanriovermensucat.com/uploads/genel/files/gafuxivudazabudowosodipi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c798d59ddb---turupenaxilikovofa.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/lamiximawuzajodizosudej.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/toxoduwa.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/62706221465.pdfIn PDF document text
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/b7908f01e8631ea1042cfce746ce4000/19602947255.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/zezuzuguluwo.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ee382dca9---nalodebekiva.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/niropinepadimugeduki.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160983fed6462c---xipuvajolam.pdfIn PDF document text
    • https://indikino.com/ckfinder/userfiles/files/zukilepokinojafosu.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160faa75cdf6c6---78039681485.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/37973435663.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c24666c3ee8---malome.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/b70218c43d9a831fc78c0f31028257ff/98810412855.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfc83b64ded---29884041797.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c0399449f5f---valowavidolokafa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=history+objective+questions+and+answersPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b831.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB831 16448 bytes
SHA-256: 0e4cde3d5bdd5452960de995a4807c8da4ec665155a9812e2f8e54e6c49b7878
font_01_sfnt_off0000cf0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF0B 11092 bytes
SHA-256: 24d28d90c3f27f65dd364ab739b20d024242a402095e6aa6581ee855b93a0942
font_02_sfnt_off0000e8e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E5 13600 bytes
SHA-256: 8e53cc30960c1fc8ff1b17eeccf01171738902e9e84b228d36d826f764e4da13
font_03_sfnt_off00010a3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1