Malicious PDF — malware analysis report

Static analysis result for SHA-256 21745ace03063989…

MALICIOUS

PDF

36.3 KB Created: 2020-08-12 17:24:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1045431a758e93641b63ad564bb8b651 SHA-1: 3b7d370697c033ccb7559031eaaa082a10982a1e SHA-256: 21745ace030639892320ac0ffdbfcc55b7ef7adda11def35e4fb17ffe7e0f464
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded links, many of which point to domains associated with link farms and redirectors, as indicated by the PDF_SEO_LINK_FARM and PDF_MALICIOUS_REDIRECTOR_LINK heuristics. The document body, though partially corrupted, contains text suggesting it is disguised as lecture notes to entice clicks on these malicious links. The ML_NYX_PDF_MALICIOUS heuristic further supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ttraff.cc/pify?keyword=lecture+notes+on+calculus+of+variations+pdf
    • http://turewano.jacketboosters.com/uploads/1/3/1/4/131407164/9282832.pdf
    • http://files.hsiaoaiwang.com/uploads/1/3/2/6/132682615/7248143.pdf
    • http://files.dechase.com/uploads/1/3/2/6/132695714/dofojuko.pdf
    • https://cdn.shopify.com/s/files/1/0432/9881/6150/files/kixigidofu.pdf
    • https://cdn.shopify.com/s/files/1/0435/5263/7091/files/38484473908.pdf
    • https://cdn.shopify.com/s/files/1/0435/4726/3128/files/93242815803.pdf
    • https://cdn.shopify.com/s/files/1/0432/0293/6992/files/causes_of_primary_amenorrhea.pdf
    • https://cdn.shopify.com/s/files/1/0437/1644/4315/files/togajugabafezitoxit.pdf
    • https://cdn.shopify.com/s/files/1/0433/6546/6270/files/candombl_de_angola_fundamentos.pdf
    • https://cdn.shopify.com/s/files/1/0428/2135/3635/files/instrumentation_engineering_interview_questions.pdf
    • https://cdn.shopify.com/s/files/1/0431/3733/5464/files/pilolunupexenapelemuxefe.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/32829552166.pdf
    • https://cdn.shopify.com/s/files/1/0451/0570/9219/files/bescherelle_italien_le_vocabulaire.pdf
    • https://doi.org/10.1142/9789813144699_fmatterhttps://doi.org/10.1142/9789813144699_0001https://doi.o
    • 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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000524a.bin
ab092491a98dca88dcbc43b40feebc71ae002e9c149c0d69ec7f481b7433e712
pdf-font-stream PDF embedded font (sfnt) at offset 0x524A 5148 bytes
font_01_sfnt_off000063df.bin
bf4e26ed4dd7501ada4758a4ae01a389992ca9293d4ba6e8c714eee277fadd50
pdf-font-stream PDF embedded font (sfnt) at offset 0x63DF 9716 bytes