Malicious PDF — malware analysis report

Static analysis result for SHA-256 93689e51071a7eae…

MALICIOUS

PDF

36.9 KB Created: 2020-08-16 18:36:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 39c73824c18af8d4c4cbaba19574c7fd SHA-1: 07c39874b25825e4e5146ecf340ad1773c2dc4c1 SHA-256: 93689e51071a7eae5d02bdb10396d29ec03870da1dcedcc7a86a4513fad3ce71
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic identifying a link to a known malicious redirector at `ttraff.com`. The document body, though partially corrupted, suggests a lure related to an 'adjectives worksheet pdf'. The presence of a link farm and the ML classifier's high confidence further support malicious intent. The primary attack pattern involves redirecting the user to malicious infrastructure.

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.com/pify?keyword=predicate+nouns+and+adjectives+worksheet+pdf
    • http://files.rinconcasa.com/uploads/1/3/1/0/131071043/3401508.pdf
    • http://files.meleneyequipment.com/uploads/1/3/0/7/130739918/sudimupi.pdf
    • http://werunimub.snscustomfloats.com/uploads/1/3/1/4/131407222/32f995.pdf
    • https://cdn.shopify.com/s/files/1/0431/5725/8401/files/bioremediasi_perairan.pdf
    • https://cdn.shopify.com/s/files/1/0429/5265/5002/files/mumeburejejosetew.pdf
    • https://cdn.shopify.com/s/files/1/0435/3445/0840/files/sezidesevavetaditagupupul.pdf
    • https://cdn.shopify.com/s/files/1/0436/2646/3385/files/satum.pdf
    • https://cdn.shopify.com/s/files/1/0430/7274/9721/files/53507070498.pdf
    • https://cdn.shopify.com/s/files/1/0433/4272/5275/files/receipt_format.pdf
    • https://cdn.shopify.com/s/files/1/0440/1253/5958/files/nelibolove.pdf
    • https://cdn.shopify.com/s/files/1/0427/4782/2236/files/sitobivelitesurava.pdf
    • https://cdn.shopify.com/s/files/1/0434/0262/5178/files/ginezupawemukakifo.pdf
    • https://cdn.shopify.com/s/files/1/0430/1075/2663/files/zanemuk.pdf
    • https://cdn.shopify.com/s/files/1/0432/3803/1518/files/tebolotakarelusi.pdf
    • 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_off0000514c.bin
445092daf0615b340cea753e37fd00d3b8863ae240e8c972b4d66502fc5933bc
pdf-font-stream PDF embedded font (sfnt) at offset 0x514C 5504 bytes
font_01_sfnt_off00006414.bin
fb7ce64c77618b2e9356230a44ad6fb5bf872d83b609093a373e349e16901748
pdf-font-stream PDF embedded font (sfnt) at offset 0x6414 10096 bytes